Heat treatment after welding on the bottom of hydraulic cylinder
The processing quality of the bottom of the hydraulic cylinder also needs to be taken seriously. Normally, after the cylinder bottom is welded, heat treatment is required. Why is this? Let's talk about the heat treatment after welding of the bottom of the hydraulic cylinder.
After heat treatment, the residual stress after welding can be well eliminated, so that the performance of the bottom of the hydraulic cylinder is more stable and meets the requirements of use.
1. After the welding is completed, a part of the stress will remain in the material itself. This is because during the welding process, the temperature of the bottom of the hydraulic cylinder will be unevenly distributed, so residual stress will inevitably appear in this process. The method that is often used to eliminate residual stress is to perform high temperature tempering, which uses the material to reduce its stress under the action of high temperature.
2. We need to choose an appropriate heat treatment method. Normally, after welding, there are two methods to choose from. One method is single high temperature tempering, and the other method is normalizing plus high temperature tempering. However, in comparison, the former does not well achieve the effect of eliminating the stress on the bottom of the hydraulic cylinder, so it is often necessary to perform high temperature tempering to achieve the goal. Moreover, the former is generally only suitable for heat treatment after assembly and welding of large-scale ordinary low-carbon steel containers assembled on site.
3. Choose an appropriate heating method for the heat treatment of the bottom of the hydraulic cylinder after welding. We can choose induction heating or radiant heating. However, as long as the induction heating method is suitable for the eddy current and hysteresis of the steel in the alternating magnetic field, only simple equipment is needed for induction heating. The latter usually includes flame heating method, resistance furnace heating method and infrared heating method.