Heat Treatment Process of Tin Bronze Contacts

Some switchgear contact parts are made of tin bronze material, which requires good elasticity, wear resistance, anti-magnetic and corrosion resistance. Due to the complex shape of the part, in the process of stamping and bending, in order to make the workpiece have sufficient toughness while maintaining a certain strength and elasticity, and avoid cracking at the corners when the workpiece is bent, it is necessary to The material workpiece is subjected to the necessary annealing treatment. For this reason, it is very necessary to formulate suitable processing procedures and heat treatment processes in order to meet the requirements of part design and production.
1. Contact parts material and heat treatment requirements
(1) Material 2.5mm thick tin bronze sheet.
(2) Heat treatment requirements After annealing, the workpiece has sufficient toughness while maintaining a certain strength and elasticity, so that there should be no cracking or processing difficulties due to work hardening during the stamping and bending process.
2. Problems that are prone to occur in the process of stamping and bending of contacts
When the tin bronze plate is directly processed without corresponding heat treatment, a certain work hardening phenomenon occurs after the contact material is punched and sheared (including punching, shearing groove, etc.) into corresponding plate conditions, resulting in subsequent bending. In the process of processing, the disadvantages of breaking the punch and increasing the wear of the die easily occur; at the same time, due to insufficient toughness, the workpiece is prone to cracking, difficult to form, and affects the final forming size of the part during the bending process. To this end, it is necessary to formulate suitable processing lines and heat treatment processes to meet the design requirements and production requirements of parts.
3. Scheduling of parts processing route
According to the shape of the part, the characteristics of the processing equipment and the method of use, and the change of the material properties of the part during the processing, the processing route can be roughly scheduled as follows: knife and scissors → stamping → annealing → bending → annealing → bending forming → surface processing, etc.