Professional undertaking: plasma nitriding of carbon steel, alloy steel, tool steel, stainless steel, high speed steel, cast iron, powder metallurgy and other metal parts.
Brief introduction of plasma nitriding;
Ion nitriding was invented by French B.Berghaius in 1932. At present, China is at the leading level in some theories and technologies of ion nitriding. The technology is carried out in a nitrogen-containing atmosphere of 0. 1- 10 Torr, with the furnace body as the anode and the workpiece to be treated as the cathode, and several hundred volts of high-voltage direct current is applied between the cathode and the anode. Glow discharge will produce a glow similar to neon light to cover the surface of the workpiece to heat it up, and at the same time, surface nitriding will be strengthened by cathode sputtering and ionization.
Effectively removing the passivation film on the metal surface and forming a hardened protective layer on the surface of the workpiece can significantly improve the surface hardness of the parts, enhance the wear resistance and bite resistance, and improve the fatigue strength and corrosion resistance, thus improving the quality of parts and dies, prolonging the service life and obtaining obvious economic benefits.
I. Advanced technology
1, ion nitriding: the nitrided layer with high toughness γ′ phase (white bright layer) or without white bright layer can be obtained, with good wear resistance and corrosion resistance and high fatigue strength.
2. Ion nitrocarburizing (ion soft nitriding) and ion nitrocarburizing: short time, high benefit, and a wear-resistant and scratch-resistant white layer with ε phase as the main component, especially suitable for carbon steel and iron castings.
3. Plasma sulpho-carbonitriding: short time, high benefit, flexible control of composite layer, various types of infiltrated layers, thick ε phase, white bright layer and FeS layer with self-lubricating function, and extremely small friction coefficient.
Second, the performance is excellent.
1, environmental protection and energy saving
Because ion nitriding is directly heated by glow discharge, rather than relying on chemical reaction, ionized nitrogen-containing gas is used for nitriding treatment, and uniform temperature can be obtained. Compared with indirect heating method, the efficiency can be improved by more than 2 times (the energy consumption is only 40-70% of gas nitriding, and the gas consumption is only a few percent of gas nitriding), and there is no need for environmental protection facilities to prevent pollution. Therefore, ion nitriding is also called' environmental protection nitriding' in this century.
2. seepage velocity is fast
Plasma nitriding not only has strong nitriding ability, but also can activate the surface of workpiece, resulting in defects of accelerated absorption and diffusion, so plasma nitriding can greatly shorten nitriding time, especially shallow nitriding. For example, when the depth of nitrided layer is 0.3 ~ 0.5 mm, the ion nitriding time is only 1/3~ 1/5 of that of ordinary gas nitriding time.
3. Minimum deformation
Because ion nitriding is carried out in vacuum, an oxidation-free machined surface can be obtained without damaging the smoothness of the surface of the workpiece to be treated. Moreover, if it is treated at low temperature (nitriding can be carried out at 380℃), the deformation of the workpiece to be treated is very small, which can solve many problems that can not be solved by conventional heat treatment, meet the requirements of high-precision parts, and is suitable for the finished product treatment without mechanical processing after treatment.
4, good toughness
After gas nitriding and salt bath nitriding, a thick (more than 20μ m) compound layer usually appears on the surface of the workpiece, which is due to the uneven mixed layer composed of E+γ′, and the inner layer is a diffusion layer. Therefore, three-phase micro-stress is generated in the composite. If a little external force is applied in this direction, microcracks will occur, which will gradually expand and peel off the whole composite layer. The compound layer of nitrided steel containing chromium and aluminum is very brittle, and it will generally be worn off after gas nitriding. However, by controlling the nitrogen-carbon content ratio or nitrogen-hydrogen ratio in the atmosphere, ion nitriding can obtain a 5-30μ m ε-phase single-phase layer with less brittleness or a 0-8μ m thick ductile γ'-phase single-phase layer, and can also obtain a compound-free layer with better toughness, only a diffusion layer, so it can be installed directly without grinding. To sum up, plasma nitriding can freely adjust the phase composition and structure of compound layer by adjusting the ratio of nitrogen, hydrogen and other gases (such as carbon, oxygen, sulfur, etc.). ), so as to obtain the expected mechanical properties.
5, do not need blunt treatment
Due to the obstruction of passivation film on stainless steel surface, traditional gas nitriding must be passivated, because the process is very complicated, difficult to control and the effect is difficult to guarantee. Ion nitriding can effectively remove the passive film formed by sputtering, so it provides a new way for the surface strengthening treatment of stainless steel.
Ion nitriding is widely used in metallurgical machinery, light industrial machinery, automobile industry, railway machinery, marine machinery, textile machinery, chemical machinery, coal mining machinery and so on.
General machinery manufacturing: gears, gear rings, transmission shafts, screws, cylinders, valve bodies, precision coupling parts, disc cams, hydraulic components, reducer parts, turbines, scroll bars, boring bars, etc.
Automobile and motorcycle industries: crankshaft, camshaft, gear, cylinder liner, valve, connecting rod, torsion plate, brake control system, piston pin, reducer synchronization ring and nozzle;
Tools: high-speed steel drill, milling cutter, reamer, tap, hob, gear shaper cutter, broach, etc. After treatment, the effect of processing stainless steel is particularly remarkable.
Moulds: various plastic moulds, rubber moulds, cold-drawn moulds, die-casting moulds, extrusion moulds, hot forging moulds, glass moulds, trimming moulds, bending moulds, etc. For dies with low pressure, medium carbon alloy steel in normalized or quenched and tempered state can be nitrided;
Textile machinery: roller, winder, elastic silk machine, hot rail, steel collar, etc.
It is also widely used in machine tools, locomotives, petrochemicals, mines, light industrial machinery, military guns and other industries.
Commonly used nitriding materials are listed in table 1.
Category number
Carbon structural steel 08 (f), 10, 15, 20, 45, 60
Alloy structural steels 20MnV, 20SiMn2MoV, 25SiMn2MoV, 37 SiMn2MoV,
15MnVB、20 MnVB、40 MnVB、20Si MnVB、 15Cr、20Cr、
30Cr、35Cr、40Cr、 15CrMo、38CrSi、20CrMo、30 CrMo、
35 CrMo、42 CrMo、 12 CrMoV、35 CrMoV、25 Cr2MoVA、
20 Cr 3 mova、38CrMoAl、20CrV、40 CrV、50 CrVA、 15CrMn、20CrMn、40CrMn、20CrMnSi、25 CrMnSi、30 CrMnSi、30CrMoAl、30CrMnAl、30CrMnSiA、20CrMnMo、40 CrMnMo、
20 CrMnTi
30 CrMnTi、 12Cr2Ni4、20 Cr2Ni4、20CrNiMo、40CrNiMoA、
45CrNiMoVA、 18Cr2Ni4WA、25 Cr2Ni4WA
stainless acid resistant steel
Heat resistant steel 1cr 17, 1Cr 13, 2Cr 13, 7Cr 17, 1Cr 18Ni9.
1Cr 13Mo、4Cr9Si2、4Cr 14NI 14W2Mo
Alloy tool steels Cr 12, Cr 12MoV, Cr6WV, 5CrMnMo, 5CrNiMo, 3Cr2W8V,
4Cr5MoSiV 1、4Cr5MoSiV
High-speed tool steels W 18Cr4V and W6Mo5Cr4V2.
Nodular cast iron Qt 600-3 and QT700-2
Titanium alloys TA2, TA4, TA7
Table 2 Surface hardness and depth index of common materials after ion nitriding treatment
Ion nitriding technology of material preheating treatment
Type, material, brand, method, hardness, surface hardness and penetration depth.
Annealing of carbon steel and pure iron 300-400 0. 15-0.3
10 15 20 raw materials 350-430 0.2-0.3
Normalizing or tempering HB 180-200 450-550 0.2-0.5
Quenching and tempering of alloy structural steel 20Cr 500-550 0.2-0.5
20CrMnTi normalizing or tempering HB 180-200 550-600 0.2-0.5
40Cr tempering 550-650 0.3-0.5
42CrMo tempering 550-700 0.3-0.5
Nitrided steel 38CrMoAi quenched and tempered 900- 1 100 0.2-0.5
30CrMoAi tempering HB 217-223 850-1050 0.2-0.5
30CrMnAi tempering HB 223-228 750-850 0.2-0.5
Tool and die steel Cr 12 quenching and tempering HRC 50 900-1000 0.15-0.3
Cr 12MoV quenching and tempering 950-10500.15-0.35
W6MO5Cr4V2 solution treatment1200-1500 0.01-0.25
3Cr2W8V quenching and tempering 900-11000.15-0.35
5 crnimo tempering HRC 45 750-900 0.3-0.5
5 crmnmo tempering 650-890 0.3-0.5
H 13 quenching+tempering 950- 1200 0+438+05-0.3
Stainless steel 2cr 13, 4cr 13 quenching+tempering 900- 1000 0. 1-0.2
1Cr 18Ni9Ni solid solution HV162900-1000 0.1-0.2
Cast iron HT20-4 as-cast HB 203 350-550 0. 1-0.3
Qt 600-2 normalizing 350-550 0. 1-0.3