1.1 What is investment casting?
1.2 What is the production process of investment casting?
1.3 What is the production method of investment casting?< /p>
1.4 What are the mechanical properties of carbon steel and alloy steel commonly used in investment casting?
1.5 What investment shells can be cast using water glass as the binder and quartz sand powder as the refractory material? Castings?
1.6 How economical is investment casting?
1.7 What issues should be considered when planning to build an investment casting workshop (or factory)?
1.8 What are the problems with investment casting? 2.1 What are the contents usually included in the process design of investment castings?
2.2 What are the requirements for the structure of investment castings?
2.3 What is Process reinforcement? What is a process hole?
2.4 What is a casting process drawing? What process parameters should be shown?
2.5 What is a casting drawing? How to draw a casting drawing?
2.6 What is a parting surface? How to select and determine a parting surface?
2.7 What is a datum plane? How to determine a datum plane?
2.8 What are the corners of castings? Need to fillet? How to determine?
2.9 What is casting slope? How to determine casting slope?
2.10 Why do castings need to have a certain machining allowance?
p>
2.11 What is the casting shrinkage of various black alloys in investment casting?
2.12 What is the total shrinkage of ZG15~55?
2.13 How to estimate precision Casting quality?
2.14 What are the basic requirements for the gating system?
2.15 What types of gating systems are there? What are the characteristics of each?
2.16 Gate What is the function of the cup? Which form is the best?
2.17 From the perspective of feeding, what are the characteristics of top pouring and bottom pouring pouring systems?
2.18 Direct pouring What is the function of the gate? What issues should be paid attention to during design?
2.19 What is the function of the cross gate? Which form is the best?
2.20 Why is the internal gate design What is the most important link in investment casting and riser design?
2.21 What are sequential solidification and simultaneous solidification? How to choose the solidification principle according to the conditions of the casting?
2.22 What is a casting? What are the hot spots? How to find the diameter of the hot spot circle on a casting?
2.23 What issues should be considered when selecting the location of the inner gate?
2.24 What should be paid attention to when determining the number of inner gates? Question?
2.25 What are the cross-sectional shapes of the inner gate? How to choose?
2.26 How to determine the cross-sectional size of the inner gate?
2.27 How to use equivalent Calculate the cross-section size of the inner gate using the hot joint method?
2.28 What is the solidification zone? What is the relationship between the width of the solidification zone and the quality of the casting?
2.29 After the pouring is completed, the shrinkage of the molten metal has an impact on the quality of the casting. What impact does the casting quality have?
2.30 What role does the riser play in the investment casting process?
2.31 What conditions must the riser meet?
2.32 How can we ensure that the solidification time of the riser is longer than the solidification time of the casting?
2.33 To fully feed the casting, does it suffice as long as the riser is large enough?
2.34 The riser is the most What kind of shape is best to adopt?
2.35 What is subsidy?
2.36 How to use internal cooling iron in investment casting?
2.37 Some parts of the casting are upward The protruding part (Figure 2.17) is always not fully poured during pouring, no matter whether it is fast pouring or slow pouring. How to solve it?
2.38 How to determine the pouring and riser system of sleeve castings?
2.39 How to determine the gate and riser system for ring type castings?
2.40 How to determine the gate and riser system for frame and strip castings?
2.41 How to determine the roulette type castings Gating and riser system of castings?
2.42 How to determine the gating and riser system of impeller castings?
2.43 How to
How to determine the gate and riser system for shell castings?
2.44 A factory produces ZG25 valve bodies (valve bodies of various sizes), and the inner gate is opened in a position without a flange. The result is a high scrap rate. , and the valve body is easy to leak, why? How to correct it?
2.45 sleeve (different sizes, Figure 2.29), ZG35, the same size sleeve pouring system has two pieces in each set, stand two on the side, The inner gate is inserted sideways; each set of 4 pieces is placed sideways and two are placed sideways. The scrap rate is very high due to cracking when the inner gate is pushed up. Each group of different sizes is stacked and placed vertically. There is less cracking when the inner gate is pushed up. Why?< /p>
2.46 Lower valve seat of air compressor valve (Figure 2.30), ZG45, net weight 0?7kg, mold shell temperature 600~650℃, pouring temperature 1600℃, pouring time 7s, holding time ≥120min, results The cracks in the casting are very serious. Sometimes there are no cracks at the top, and sometimes there are no cracks at the bottom, and sometimes there are no cracks at the top. Why?
2.47 The narrow groove of the casting shown in Figure 2.31 is difficult to cast. How to solve it?
2.48 The bicycle bottom bracket part shown in Figure 2.33 has a very thin wall. Two ?10 ingates are opened at the bottom. The cross-section of the sprue is 35mm×35mm and the length is 320mm. Welding three layers on four sides***12 However, there are many waste products due to insufficient pouring. How to solve the problem?
2.49 What should be paid attention to in the casting process when pouring 18.8 stainless steel castings?
2.50 What is investment casting filtration technology? 3.1 What are the requirements for the structure of the molding?
3.2 What is shrinkage? How to determine the total shrinkage rate of the molding cavity size?
3.3 How to determine the size of the molding cavity?< /p>
3.4 How to determine the dimensional accuracy and surface roughness of the molding?
3.5 What types of moldings are commonly used in investment casting?
3.6 How to make and maintain them Steel profiling?
3.7 What are the common preparation methods for low melting point alloy profiling?
3.8 How to make and maintain low melting point alloy profiling?
3.9 How to make plastic moldings?
3.10 What are the characteristics of the gypsum used to make gypsum moldings?
3.11 How to make gypsum moldings?
3.12 What issues should be paid attention to when using gypsum molding?
3.13 How to design an automatic wax molding machine?
3.14 Methods to form complex inner cavities of castings What are they?
3.15 How to make a steel core?
3.16 How to make a soluble core?
3.17 Seven pieces of urea were used in the trial production of hydraulic turbine blades When dissolving the core, six of the pieces quickly dissolved. The other piece was soaked in water for a day and a night. Not only did it not dissolve, but the wax model burst. Why?
3.18 How to make a ceramic mold? Core?
3.19 How to make a water glass core?
3.20 Without using urea core and ceramic core, how to pour porous castings using general technology?
3.21 When pressing the investment mold with a protruding part in the upper half mold, the protruding part is always unclear in outline. How to eliminate it (Figure 3.5)?
3.22 The blade casting in Figure 3.6 has both upper and lower curved surfaces. No processing, but the thick part of the wax mold always shrinks downward when cooling. How to solve it?
3.23 Many structures are similar to the pressing molding in Figure 3.8, and the end face of the pressed investment mold is always concave or How to solve the problem if it is broken?
3.24 To prevent the opening and deformation of the wax model, are there any other methods besides using inserts and tie bars? 4.1 What are the basic requirements for the raw materials of the mold material?
4.2 What are the main properties of paraffin wax and stearic acid mold materials?
4.3 Why is the issue of substituting stearic acid raised? What are the main substitute materials?
4.4 Paraffin wax and stearic acid mold materials When the material is melted, why is the water-isolated heating method used instead of direct heating with an electric furnace?
4.5 What medium-temperature molding materials are currently produced and used at home and abroad?
4.6 Low-molecular polyethylene molding materials What's going on?
4.7 How to adjust the composition of paraffin wax and stearic acid molding materials according to climate characteristics?
4.8 Why is it necessary to stir when preparing molding materials? How to prepare molding materials?<
/p>
4.9 Can you introduce a molding material that has better performance than paraffin and low molecular polyethylene molding material and can be self-prepared?
4.10 What are the job responsibilities of staff who prepare molding materials? ?
4.11 How to use parting agent when pressing investment mold?
4.12 What effect does the working temperature of pressing have on the quality of investment mold?
4.13 Mold making site What effect does temperature have on the quality of the investment mold?
4.14 What effect does the temperature of the mold material have on the quality of the investment mold?
4.15 Why does the surface of the investment mold bubble and annular structure when it exceeds 32°C? All sections are detached?
4.16 What impact does the injection pressure have on the quality of the investment mold?
4.17 What is the relationship between the wax injection port and the molding?
4.18 What additives are good to use in the investment cooling water?
4.19 Why is it not advisable to use the free pouring method to obtain the investment mold for gypsum molding?
4.20 How to choose a wax pressing machine?
4.21 What is the structure and working principle of a pneumatic desktop wax pressing machine?
4.22 Pneumatic multi-head hand-pressed investment mold pressing machine What is the structure and working principle of the machine?
4.23 What is the structure and working principle of the semi-automatic wax pressing machine?
4.24 The structure and working principle of the twelve-station horizontal automatic wax pressing machine How?
4.25 What is the structure and working principle of the electric wax pressing machine?
4.26 What are the types of molding production lines?
4.27 What are the types of wax pressing machines? What are the common faults? How to eliminate them?
4.28 What operating procedures should be paid attention to when using the wax pressing machine? How to maintain and maintain the wax pressing machine?
4.29 What requirements should the investment surface meet?< /p>
4.30 How are the flash and burrs of the investment mold produced?
4.31 Why does the surface of the investment mold often shrink? How to prevent it?
4.32 Why does the investment mold appear? Will cracks appear? How to prevent them?
4.33 What is the reason for the rough surface of the investment mold?
4.34 Is there any simple method to reduce the surface roughness of the investment mold?
4.35 Why does the investment mold produce deformation, warping, cold shut or insufficient injection?
4.36 The thermal stability of paraffin wax and low-molecular polyethylene molding materials is poor, and the pressed wax molds are easily deformed. How to remedy this in operation?
4.37 When using paraffin wax and stearic acid molding materials, there will be problems when pouring The wax flakes are hard and brittle, and the investment molding machine is often damaged. How to overcome this problem?
4.38 What are the job responsibilities of the mold-making staff?
4.39 How to repair the investment mold?< /p>
4.40 How to store and keep the investment mold?
4.41 How to make the gate rod mold?
4.42 What equipment is used to make the gate rod?
< p>4.43 What is the job responsibility system for gate rod production personnel?4.44 What are the requirements for investment mold assembly welding?
4.45 How to assemble complex investment molds?
4.46 How to test the performance of wax-based mold materials? 5.1 What are the commonly used dewaxing methods?
5.2 After the mold string was dewaxed, the next day it was found that the entire pot of dewaxed water was in the form of a thin jelly. Why?
5.3 After dewaxing, a layer of jelly will precipitate on the inner and outer surfaces of the mold shell made with MgCl2 as the hardener. What is it?
5.4 Hot water dewaxing What are the key points of the process?
5.5 What are the characteristics of the steam dewaxing method?
5.6 What are the characteristics of the hot air dewaxing method?
5.7 Microwave dewaxing What are the characteristics of the far infrared dewaxing method?
5.8 What are the characteristics of the far infrared dewaxing method?
5.9 What is the "saponification reaction" of the mold material?
5.10 In dewaxing During the waxing process, the dewaxed water occasionally turns dark milky white, and wax and water gradually become indistinguishable. The entire pot is filled with saponified substances containing bubbles. There are more and more saponified substances containing bubbles. They rise rapidly and overflow out of the pot in large quantities. Why?
5.11 How to determine the content of saponified matter?
5.12 ??What are the methods for recycling mold materials?
5.13 Why must the mold materials after lost wax be recycled? Process?
5
.14 ??How is the recycling of mold materials performed?
5.15 What factors can cause discoloration of low-temperature mold materials during use?
5.16 Old mold materials are repeatedly subjected to acid treatment Why can't the dark red color be eliminated?
5.17 What are the job responsibilities of dewaxing and recycling staff?
5.18 Why does the mold shell crack during dewaxing?
< p>5.19 How to recycle old mold materials with hydrochloric acid?5.20 How to eliminate the excessive acid content of mold materials that have been recycled with acid?
5.21 For mold materials that have turned dark brown or How to eliminate the color of reddish-brown mold material?
5.22 When recycling the mold material, there are many white dots floating in the mold liquid. How to eliminate them?
5.23 The dewaxed mold How to deal with the white saponified matter inside the shell?
5.24 What are the key points to pay attention to when recycling paraffin and stearic acid mold materials by acid method?
5.25 How to reasonably choose a cheap and practical Recycling of mold material pots (barrels)?
5.26 How to recycle the mold material by electrolysis method? 6.1 What are the requirements for the performance of the mold shell?
6.2 What raw materials are commonly used for shell making?
6.3 Quartz material What are the process requirements for shell making?
6.4 What are the performance characteristics of refractory mud?
6.5 What are the performance characteristics of sagger sand powder?
6.6 Aluminum What are the main specifications and properties of soil?
6.7 What are the binders for shell making?
6.8 What are the process performance indicators of water glass?
6.9 Preparation How to choose the process parameters of water glass when coating?
6.10 What is the principle of increasing the modulus of water glass?
6.11 How to deal with low modulus water glass?
6.12 Why does water glass deteriorate if it is not stored properly?
6.13 Can high-modulus and low-modulus water glass be blended together?
6.14 Treatment of water glass with ammonium chloride improves the How to operate the modulus?
6.15 Can industrial hydrochloric acid be used to increase the modulus of water glass?
6.16 How to accelerate the dissolution process of precipitates during water glass treatment?
6.17 What should you do when the modulus of water glass is appropriate but its density is too low?
6.18 What should you pay attention to when using water glass that has been treated with increased modulus?
6.19 How to measure the modulus of water glass?
6.20 How to measure the condensation time of water glass?
6.21 What is the relationship between the modulus (M) and density (d) of water glass? Is there a table to check?
6.22 How to control the quality of water glass coating?
6.23 How to measure the viscosity of coating? What effect does it have on the quality of the mold shell?
< p>6.24 Can the quality of water glass coating be controlled by measuring the density of the coating?6.25 What is the coating ratio? What effect does it have on the quality of the mold shell?
6.26 Temperature What impact does it have on the performance of water glass coatings?
6.27 The strength of the mold shells produced in the precision casting workshop of a certain factory changes periodically. When new coatings are added, the strength is better, but after a while it deteriorates again. Why? ?
6.28 What is the function of surface coating? How to prepare it?
6.29 What is the amount of degreasing agent, defoaming agent and penetrant added?
6.30 Why must the penetrant be diluted with water before being added to the paint?
6.31 Can tung oil or clay be added to the surface paint?
6.32 What is a fine grain paint?
6.33 Should the refractory mud added to the reinforcing layer coating be made of raw material or clinker?
6.34 When preparing the reinforcing layer coating, if water glass is added according to the specified ratio, the coating will The viscosity is extremely thick. If the viscosity is appropriate, add 1/3 less powder than the prescribed ratio. Why?
6.35 What is the function of the reinforcement layer coating? How to prepare it?
6.36 The top layer coating must be naturally dried before entering the hardening pool, while the reinforcement layer coating only hardens after entering the pool. Drying is done only after the
So dry, why?
6.37 What is the "maturation period" of paint? How to store paint?
6.38 What are the job responsibilities of paint preparation personnel?
6.39 The shell making process includes Which steps?
6.40 What operating procedures should be paid attention to when applying paint?
6.41 Why should we spread sand after applying paint? What are the methods of spreading sand?
6.42 When the upper layer of paint has just been soaked and has not been sanded, it will flow off within a few minutes. How to overcome it?
6.43 Is it necessary to set up a special exhaust mechanism while soaking the paint? How to make the molded shell more breathable?
6.44 When the molded shell is taken out of the hardening pool, excess ammonium chloride should not be washed away with water? Does the delamination of the molded shell have anything to do with this?< /p>
6.45 What is the role of natural drying before hardening of water glass shell?
6.46 What is the essence of chemical hardening of water glass shell?
6.47 How to prepare chlorine Ammonium hardener?
6.48 Why does ammonium chloride hardener need to be tested and adjusted regularly? How to adjust?
6.49 Sometimes in production, the hardener does not reach the specified concentration but the bottom of the pool is What is the phenomenon of depositing massive ammonium chloride?
6.50 Why is it necessary to control the Na2O content in the shell to 0.7% to 0.9% during the shell making process?
6.51 Many factories have set a limit value for the Na2O content in water glass. Water glass exceeding this value cannot be used. Why?
6.52 How to determine the Na2O content in coatings and mold shells?
6.53 How to dissolve bulk solid sodium silicate to make water glass?
6.54 Why can’t the NaCl content in NH4Cl hardener exceed 8%?
6.55 Hardener A large part of the ammonium chloride falls on the bottom of the pool and does not dissolve, with a content of 20% to 23%. Why (water temperature 0 to 3℃)?
6.56 The factors that affect the hardening speed of the water glass shell are: Which?
6.57 What effect does hardening time have on the quality of the mold shell?
6.58 How to detect the hardening effect of the mold shell?
6.59 The mold string is in the self-hardening groove It was still dripping 30 minutes after it was picked up. Later, when 0.05% Agricultural Milk 130 was added to the hardening liquid, the situation immediately changed significantly. Why (Agricultural Milk 130 has been used in the reinforcing layer paint)?
6.60 What is Nongru 130?
6.61 The surface coating bulged and separated from the investment mold. When it was first discovered, the hardener temperature was about 10°C. The hardener was heated. The situation immediately improved after hardening; when it was discovered for the second time, the hardener detached without heating. Why?
6.62 What is the role of natural drying after hardening? How to control the drying time?
6.63 Why should we replace ammonium chloride hardener?
6.64 How to use chlorine Calcium chloride hardener?
6.65 How to use magnesium chloride hardener?
6.66 How to prepare magnesium chloride hardener?
6.67 Pay attention when using magnesium chloride as hardener for hardening. What?
6.68 According to the information, the magnesium chloride hardener is prepared according to magnesium chloride:water = 2:1, but in production, the magnesium chloride hardener is prepared according to magnesium chloride:water = 1:2. Who is right and who is wrong? ?
6.69 How to use polyaluminum chloride hardener?
6.70 How to use crystalline aluminum chloride hardener?
6.71 When aluminum chloride is used as hardener What does B mean?
6.72 Will the composition of aluminum chloride hardener change during use? How to adjust it?
6.73 How to measure basic (poly) chlorine The content of Al2O3 in aluminum chloride hardener?
6.74 How to determine the basicity B in basic (poly) aluminum chloride hardener?
6.75 Compare ammonium chloride and crystal What is the difference between the two hardeners aluminum chloride?
6.76 Why is the reaction speed of hardening with crystalline aluminum chloride solution slower than that with ammonium chloride solution?
6.77 What is the alternate hardening process?
6.78 New
Which material is good for the hardening tank for manual encrustation?
6.79 How to prepare water glass and polyaluminum chloride coating for alternate hardening?
6.80 Water glass and polychloride What are the characteristics of the alternating hardening shell-making process of aluminum paint?
6.81 What is the shell-making process of mixed paint?
6.82 What are the characteristics of the hardener hardening process for mixed paint?
6.83 What are the characteristics of alternate hardening of mixed coatings?
6.84 What are the principles and characteristics of electrophoretic shell making?
6.85 What are low-strength shells and high-strength shells? ?
6.86 How to comprehensively use shell-making materials?
6.87 How to reduce the surface roughness of castings from the perspective of shell-making?
6.88 What is ethyl silicate? Ester? What substances need to be added for the hydrolysis of ethyl silicate?
6.89 How to calculate and determine the additives of the hydrolyzate?
6.90 What are primary hydrolysis, secondary hydrolysis and comprehensive hydrolysis?
6.91 How to prepare ethyl silicate adhesive coating?
6.92 How to prepare ethyl silicate coating?
6.93 How to make ethyl silicate coating Shell?
6.94 What are the characteristics of the rapid shell making process of ethyl silicate and bauxite?
6.95 Sometimes the strength of ethyl silicate shell is not very high, why?
6.96 Why is the ethyl silicate molded shell prone to delamination?
6.97 The ethyl silicate molded shell often swells during the coating or drying process. Why?
6.98 Can ethyl silicate paint be used as the surface layer, and ordinary water glass paint be used as the reinforcing layer?
6.99 Why does the surface of the ethyl silicate shell also grow? White frost?
6.100 What is silica sol adhesive?
6.101 How to use silica sol paint to make shells?
6.102 What are the commonly used shell making equipment?
6.103 What are the types and structural characteristics of commonly used paint mixers?
6.104 What are the structures and working characteristics of turntable shell making machines?
6.105 M384 automatic shell making What are the structure and working characteristics of the machine?
6.106 What are the structure and working characteristics of the suspended shell making production line?
6.107 The structure and working characteristics of the suspended chain double spreader shell making production line What are the characteristics?
6.108 How to maintain and maintain coating shell making equipment during use?
6.109 What are the common defects of shells?
6.110 Shell making The first layer of paint is unevenly distributed, but the second layer is evenly distributed. Why?
6.111 The shell-making process procedures remain unchanged, except that high-aluminum powders from different origins are used, and the shell is made, dewaxed, and roasted. Later, cracks often occur on the four edges and bottom of the gate rod, until molten steel leaks during pouring. Why?
6.112 Why do cracks often occur in ethyl silicate mold shells during operation?
< p>6.113 How to prevent ethyl silicate shell from cracking?6.114 Why is the shell strength low?
6.115 How to prevent shell delamination?
6.116 Why does the shell deform?
6.117 Why does the shell bulge and how to prevent it?
6.118 Why does the surface of the shell grow "white hair"?
6.119 What are the job responsibilities of coating and shell making staff? 7.1 Why do water glass binder molded shells need to be fired?
7.2 Sometimes the entire section of the fired molded shell is black. Can this kind of shell be used?
7.3 Why do molded shells need to be baked? Will the shell crack and collapse when it is baked to 750℃?
7.4 During the baking process of the molded shell, the molded shell will expand and contract. Why is it mainly the transformation of silica (quartz)?
< p>7.5 White hairy precipitates are often found on the surface of water glass molded shells. Why?7.6 Cracks or even micro-cracks are often found in molded shells before pouring. How to overcome them?
7.7 How to check the roasting quality of the molded shell?
<p>7.8 What are the commonly used equipment for shell roasting?
7.9 Can a coal-fired reverberatory furnace be used to bake the shell?
7.10 Low carbon steel plate can be used as a box type after aluminizing How to operate the bottom plate of the electric furnace?
7.11 Can the effect of shell roasting be improved in the box-type electric furnace?
7.12 What are the job responsibilities of the shell roasting staff? 8.1 What are the casting properties of alloys?
8.2 What are the casting properties of cast steel?
8.3 What are the casting properties of cast iron?
8.4 The casting properties of cast non-ferrous alloys How?
8.5 What are the characteristics of cast carbon steel, low alloy steel and high alloy steel?
8.6 What are the types of commonly used cast non-ferrous alloys? How to indicate the grades of cast aluminum alloys?
8.7 What are bronze, brass and special brass? Tin bronze, aluminum bronze, yellow How is the grade of copper expressed?
8.8 What are the investment casting metal smelting equipments?
8.9 What is an acidic furnace? What is an alkaline furnace?
8.10 What principles should be used to choose acidic furnace lining or alkaline furnace lining?
8.11 What is the structure of electric arc furnace?
8.12 What is the working principle of electric arc furnace?
8.13 How to make electric arc furnace lining? How to repair electric arc furnace lining?
8.14 What are the key points of alkaline electric arc furnace oxidation steelmaking process?
8.15 Alkaline electric arc furnace does not oxidize What are the key points of the steel-making process?
8.16 What are the key points of the acid electric arc furnace oxidation steel-making process?
8.17 There is a 0.25t three-phase electric arc furnace that takes more than an hour to make a furnace of medium carbon steel. How to speed up steelmaking?
8.18 Why does a small electric arc furnace remelt quickly? The steel produced by the electric arc furnace steelmaking method and the oxidation method are relatively close in all aspects?
8.19 What are the characteristics and operating points of the electric arc furnace rapid steelmaking process?
8.20 Electric arc furnace steelmaking saves energy What are the ways of electricity?
8.21 How to classify induction electric furnaces?
8.22 What are the melting characteristics of induction electric furnaces?
8.23 How to make induction electric furnace crucibles?
8.24 How to repair the crucible of an induction furnace?
8.25 What role does boric acid play in the furnace lining material?
8.26 The alkaline furnace of a certain factory has a very short age. There are only 23 furnaces on average. Can improvements be made in furnace construction materials?
8.27 The acid lining life of power frequency furnaces varies. How to improve the lining life?
8.28 Acid induction What is the operating process of electric furnace steelmaking?
8.29 What are the properties of graphite powder? Can it be used as a carburizer?
8.30 Why can broken electrode blocks be used to increase carburization? Coke is used to increase carburization. Can carbon be used?
8.31 Can dephosphorization and desulfurization be used in acid induction electric furnace steelmaking?
8.32 Can cullet be used to make slag during acid furnace steelmaking operations?< /p>
8.33 How to control the sulfur and phosphorus content in molten steel?
8.34 What is the operating process of alkaline induction electric furnace steelmaking?
8.35 Using 150kg medium frequency induction electric furnace What measures should be taken when the appearance of the steelmaking crucible turns red or there is a power or water outage?
8.36 Can limestone be used as a flux when using an alkaline furnace for steelmaking?
8.37 Induction electric furnace melting How to decarburize cast steel?
8.38 Are alloy recovery rate (yield) and burning loss rate the same thing?
8.39 How to use gas cutting slag to remove slag from carbon steel melted in intermediate frequency furnace Carbon?
8.40 What are the structural characteristics of the power frequency coreless induction electric furnace?
8.41 What are the structural characteristics of the power frequency coreless induction electric furnace?
8.42 High frequency induction electric furnace What are the structural characteristics?
8.43 What are the structural characteristics of the vacuum induction electric furnace?
8.44 What are the principles and structural characteristics of the electroslag furnace?
8.45 How to calculate the charge ingredients ?
8.46 What are the methods to detect the temperature of molten steel?
8.47
Give an example of how to measure the temperature of molten steel?
8.48 Why is it necessary to deoxidize molten steel during the steelmaking process? How to deoxidize molten steel?
8.49 How to check the deoxidation effect of molten steel?
p>8.50 In the deoxidation stage of molten steel, is it possible to use aluminum with the strongest deoxidation ability as the deoxidizer alone to deoxidize?
8.51 Why must the order of adding deoxidizers from weak to strong when deoxidizing molten steel?
8.52 Why must deoxidation be done at the end of steelmaking production?
8.53 What is the precipitation deoxidation method?
8.54 How many deoxidation methods are there for medium frequency induction furnace steelmaking?
8.55 How to judge whether the molten steel is completely deoxidized from the surface of the poured steel sample?< /p>
8.56 The recommended values ??for the burning loss rate of elements in steel vary widely in various materials. Why?
8.57 How to judge the silicon content in molten steel?
8.58 How to use ferroalloy to adjust the pre-furnace results?
8.59 Why does the molten steel smelted with galvanized pipes as furnace charge have poor fluidity, and the castings poured with it also have many pores?
< p>8.60 Why should the charge with a lot of oil stains not be put into the furnace?8.61 When making steel with a power frequency induction furnace, some pig iron needs to be added. How to add it?
8.62 Carbon steel What are the smelting characteristics?
8.63 When ZG35 and ZG45 are smelted with 8-yuan steel head ingredients, about 70% of them often break. Why?
8.64 How to smelt ZG45 and calculate its chemical composition and charge Composition?
8.65 Adding rare earth (Re) elements to ZG45 investment castings can improve their mechanical properties. Why? How much Re should be added?
8.66 Low alloy steel (such as ZG35CrMnSi )?
8.67 How to smelt ZG20Cr?
8.68 What are the melting characteristics of alloy tool steel?
8.69 What are the melting characteristics of high alloy tool steel?< /p>
8.70 How to smelt ZG1Cr13 in an acidic induction furnace?
8.71 Why is there so much slag when smelting ZGMn13 in an acidic furnace?
8.72 What are the melting characteristics of stainless steel (ZG1Cr18Ni9Ti)?
8.73 How to smelt acid-resistant stainless steel ZG1Cr18Ni9Ti?
8.74 There are a batch of ZG1Cr18Ni9Ti castings, the material requirements are not very strict, can they be smelted in the existing acid furnace?
8.75 How to produce pearlite malleable cast iron pistons by melting in acidic medium frequency induction furnace?
8.76 How to remove slag when melting cast iron in acidic induction furnace?
8.77 Casting often occurs when melting manganese-chromium steel balls. The state structure is coarse and flaky, why?
8.78 How to use acidic medium frequency induction furnace to smelt cast iron frame parts (cast iron grade HT250)?
8.79 How to smelt low-temperature steel in medium frequency induction furnace Chromium. Rare earth cast iron?
8.80 How to use induction furnace to produce sintering machine bars (heat-resistant cast iron)?
8.81 What are the characteristics of non-ferrous metal smelting?
8.82 When a factory uses a fuel-fired copper furnace (Figure 8.1) for smelting, the refractory brick pad under the crucible always softens and deforms, causing the crucible to tilt. How to solve the problem?
8.83 Is the medium frequency induction furnace used for steelmaking? Can copper be melted?
8.84 When using an intermediate frequency furnace to melt copper, the burning loss of copper is much greater than that of a pit reflection crucible furnace. Why?
8.85 What are the job responsibilities of steelmaking personnel? Which ones?
8.86 What effect does alloy pouring temperature have on the quality of castings?
8.87 How to choose the pouring speed of castings?
8.88 What are the key points of the pouring operation process?
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8.89 What is the best temperature of the mold shell during pouring?
8.90 The molten steel ladle used in a certain factory often leaks, so the bottom of the ladle is always thickened. How should it be improved? 9.1 When can castings be shelled and cleaned after pouring?
9.2 What are the methods for shelling and cleaning?
9.3
Why is it difficult to clean and shake off castings when waxstone powder is used instead of refined quartz powder?
9.4 Can the mold shells dropped by the sand cleaning shock be reused after being crushed and screened?
9.5 Vibration How does the shelling machine work?
9.6 What is the structural principle of the electric hammer shelling machine?
9.7 What are the structural characteristics of the shelling machine modified from a rock drill?
9.8 What are the principles and characteristics of electro-hydraulic cleaning?
9.9 What are the job responsibilities of shelling and cleaning staff?
9.10 What are the cutting methods of casting gating systems?
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9.11 How to apply gas cutting method?
9.12 What are the methods for surface cleaning of investment castings?
9.13 What are the principles and characteristics of alkali boiling?
9.14 How to neutralize copper alloy castings after alkaline boiling?
9.15 Can aluminum alloy castings be cleaned of small holes or complex inner cavities by alkaline boiling?
9.16 What is the appropriate size of an alkali boiling pot?
9.17 What effect does the alkali boiling liquid that has been used many times have on the sand cleaning effect?
9.18 Alkali The higher the concentration of the cooking liquid, the better the alkaline cooking effect?
9.19 After the high-strength mold shell is out of the shell, it is difficult to boil the sand on the surface of the casting after a long time of alkaline boiling, especially at the corners. Depressions, why?
9.20 What are the principles and characteristics of electrochemical cleaning?
9.21 Why do investment castings need heat treatment?
9.22 Investment castings What are the types and specifications of heat treatment?
9.23 How to choose the heat treatment method for castings?
9.24 How to determine the heating rate of heat treatment for castings?
9.25 Pouring of steel castings How to clean and heat treat the mouth?
9.26 What are the job responsibilities of heat treatment staff?
9.27 How to prevent rust of precision castings? How to prevent "precision castings" Rust treatment? 10.1 What does the quality inspection of investment castings include?
10.2 How to check the appearance quality of castings?
10.3 How to check the intrinsic quality of castings?
10.4 How to check the chemical composition of castings?
10.5 How to check the mechanical properties of castings?
10.6 What are the reasons for the unqualified chemical composition of castings?
10.7 What is the reason for the unqualified mechanical properties of castings?
10.8 What are the common surface defects of investment castings?
10.9 What is the reason for "iron thorns" appearing on the surface of castings?
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10.10 How are "iron beans" produced?
10.11 Why do "orange peels" and "scars" appear on the surface of castings?
10.12 Often at the bottom of castings Many pits are produced, and not every casting in the same batch has them. Why?
10.13 How to prevent castings from developing blisters and slag holes?
10.14 Depressions, rat tails, sand inclusions and How are perforations produced?
10.15 Why do castings bulge and dent? What is the difference between dents and dents?
10.16 Why do castings deform? How to prevent them?
10.17 What are the characteristics and causes of pores in castings?
10.18 Some castings look good on the outside, but they are found to have pores inside after cutting. Why?
10.19 What is cold shut and insufficient pouring? How to prevent it?
10.20 Why do investment castings produce hot cracks?
10.21 Why do precision castings produce cold cracks?
10.22 Thin-walled castings with reinforced rib structures always crack at the intersection of the two ribs. How to overcome them?
10.23 What are shrinkage cavities and shrinkage porosity? How are they formed?
10.24 What is the relationship between the form of shrinkage cavities and the phase diagram?
10.25 What is the cause of brittle fracture of castings? How to prevent it?
10.26 When casting the ZG35 automobile gear shift fork, the furnace There is no problem with the chemical composition of the previous test, but sometimes it is found that a certain furnace casting
The parts are very brittle and easy to break. Why?
10.27 After the high-chromium alloy cast iron was poured into the quartz sand mold shell hot shell, black scars were found on the cross section when the inner gate was broken. Why?
10.28 Why does the surface of precision castings decarburize? How to save?
10.29 The surface of brass handicrafts cast in molds often turns black. Why?
10.30 How to weld repair castings with surface defects?
10.31 What are the job responsibilities of a final casting inspector? 11.1 What is operation and management?
11.2 What is technical management?
11.3 Are the concepts of casting quality and casting quality the same?< /p>
11.4 What is the casting scrap rate?
11.5 What is the casting yield?
11.6 What is the process yield?
11.7 How Improve process yield?
11.8 What is a process card? Why is it said to be as important a casting process technical document as a process drawing?
11.9 What are the job responsibilities in the investment casting workshop? ?
11.10 How to stabilize and improve the quality of investment castings?
11.11 What are the raw material and fuel consumption quotas for investment casting?
11.12 Process quality How many indicators should be set?
11.13 What are the contents of process quality inspection?
11.14 Can an economic responsibility system be implemented for process quality?
11.15 How to arrange each inspection Monthly production plan?
11.16 What does the production outline of investment casting production include?