Improvement Measures for Surface Cracks of Tin Phosphor Bronze

Severe casting reverse segregation is the root cause of tin phosphor bronze cold rolling cracking. The degree of ingot anti-segregation is mainly related to the conditions and methods of smelting and casting
close. In order to reduce or eliminate the impact of reverse segregation on subsequent production and product quality in production, it is necessary to adopt more suitable methods and process conditions for smelting, casting, processing and heat treatment throughout the production process.
Ingredients Control
1. The composition of old materials is complex. When smelting, the old materials of the same composition should be classified well, and they should not be confused with other old materials with different compositions. To control the content of impurity elements, especially the content of Pb
The amount of Pb should be controlled at 0.02% to 0.05%; if the content of Pb is too high, it will easily lead to cracking.
2. For each furnace of old material, the composition is tested before smelting, and the impurity elements are strictly controlled.
3. When classifying old materials, pay attention to industrial hygiene to prevent the mixing of other metal impurities
Melting control
1. Control the smelting process, appropriately reduce the casting temperature, increase the cooling intensity, improve the pull-stop process, and control the reverse segregation of Sn.
2. To reduce the phenomenon of cold rolling cracking, the key is to control the degree of reverse segregation in the casting process of the material. To control anti-segregation well, only by improving the casting method and correctly controlling the casting process
Combined with appropriate homogenization annealing and cold rolling blanking methods and processes (including appropriate rolling and coiling), product quality can be improved, costs can be reduced, and production efficiency can be increased.