1, hammer forging (knocking): hammer the deformed welding workpiece. In order to prevent the workpiece from being damaged, it is generally necessary to pad iron (preferably soft metal material), which is the simplest correction method.
2. For thin weldments, rolling equipment, such as flattening machine, can be used to roll the weld and its surroundings to achieve the purpose of correction; In the absence of equipment, heavy trucks such as trucks and forklifts can be used for wheel pressing according to actual conditions.
3. For simple small and medium-sized welded components, jack (hydraulic or screw) can be used for correction.
4. For weldments with high rigidity and strength, press (hydraulic press, hydraulic press and pneumatic machine) can be used for correction.
5. The contour can be corrected by special correction equipment (such as roller press, etc.). ).
Heating correction method
6. The heat source of heating correction method is mainly flame heating, and the main factors that determine the heating correction effect are: heating position, heating temperature and heating zone shape; Among them, the key to success is the correct choice of heating position, which is generally judged by experience for simple components; For complex parts, trial and error are needed to find the best heating position. Generally, the heating temperature can be judged by visual inspection, and can also be measured by a commercially available thermometer (meter). Generally, the heating temperature does not exceed 800℃ (cherry red).
7. Point heating: that is, heating is concentrated on a point on the metal surface, the diameter of the point is about 10-20mm, and the distance between points is 50-150 mm. After a point is heated frequently, immediately hit the heating point with a soft hammer. When the plate is struck, it should be padded with iron on the back and cooled with water (it can also be wiped with a wet rag), which is mainly suitable for correcting the wavy deformation of the plate.
8. Strip heating: the surface of the workpiece is heated into strips, and the width and density of the strips are determined according to the deformation, which is suitable for thick plates and structures with large deformation and stiffness (such as beams and columns).
9. Triangular heating (wedge heating): the heating area is triangular, and the contraction at the bottom of the triangle is greater than that at the top, which is suitable for members with large stiffness and deformation, such as bending deformation.
10, point heating, strip heating and triangle heating can be used organically and flexibly, which has a multiplier effect on the rectification work.
1 1, integral heating: suitable for weldments with large quantity and small surface. It is feasible to use integral heating, mechanical correction (strike while the iron is hot) and slow cooling for materials with strong quenching property.
Heating correction of other heat sources
12, for weldments without surface requirements, covered electrode arc welding and MIG welding can be used to weld the parts that need to be heated, so as to correct them.
13, for parts with surface requirements, TIG welding can be used to correct the parts that need to be heated, without adding welding wire (the base material does not melt).
14, induction heating correction, suitable for workpieces with small weldments and large quantities. This method has high production efficiency.
15, far infrared heating correction, suitable for large complex parts and field operations.
Matters needing attention in welding deformation correction
16, materials with good weldability can generally be corrected by heating, such as low carbon steel, stainless steel with good plasticity, and low alloy steel with low strength (14mnnnb, Q345, Q390, Q420,/kloc-0 14mmnvtixt, 10mmnpnb, etc. ).
17, flame straightening, quenching with water. Generally, you should wait until the red fades before watering. Not suitable for parts with quenching tendency or high rigidity.
18, the heating flame is generally neutral. If heating depth is required, an oxidation flame can be used.
19, the requirements of the next working procedure should be taken into account when heating correction. If the next process is hot working (welding and hot cutting), the reverse deformation required by the subsequent process can be carried out in the process of heating correction.
20, heating method can be used to correct deformation, make the building straight, on the contrary, it can make the straight component bending.
2 1, there are many kinds of fuels heated by flame: acetylene, propane, liquefied gas, natural gas, gasoline, kerosene, etc. Equipment oxygen welding torch, blowtorch, etc.
22, for large and complex components, often need more than two people heating at the same time!
23. In order to improve the calibration efficiency, it is necessary to make some special multi-head flame spraying tools to realize uniform heating and improve the calibration quality.