Most cast steel parts can only be accepted and shipped after undergoing water toughening heat treatment in the foundry. Due to the presence of a large amount of carbides in the raw materials of cast steel, the toughness is very low and it is extremely prone to fracture. So steel castings need to undergo water toughening heat treatment, and the main purpose of heat treatment is to remove carbides. When water toughening steel castings, the following two main points are required:
① The temperature for water toughening treatment. The temperature for water toughening treatment depends on the composition of high manganese steel, usually ranging from 1050 to 1100 ℃. The water toughness temperature of high manganese steel with high C content or high alloy content is taken as the upper limit. However, excessively high water toughness temperatures can cause severe decarburization on the surface of castings, leading to rapid grain growth and affecting their performance.
② The speed of heating and warming up. High manganese steel has poor thermal conductivity compared to ordinary carbon steel. Steel castings are prone to cracking when subjected to excessive stress (heating rate too fast) during the heating process. When the carbon content and mechanical properties of the inner and outer layers are significantly different due to the addition of carbon on the surface of the casting, microcracks are more likely to occur in the added carbon layer. In general, thin-walled simple parts can be heated at a faster rate, while thick walled and surface reinforced parts should be heated slowly. In production, it is common to pre heat at around 650 ℃ for 1-3 hours to make the temperature inside and outside the furnace and casting more uniform, and then quickly heat up to the temperature of the water toughening treatment process.
Changshu Hongqiao Cast Steel Co., Ltd. mainly produces various specifications of carbon steel, high, medium and low alloy steel, stainless steel, heat-resistant steel, high manganese steel, and high chromium cast iron. We provide high-quality customized steel castings for industries such as petroleum, chemical, metallurgical, mining machinery, coal mining machinery, wind power, nuclear power, and marine. We also offer customized steel castings for marine use, ABS marine engineering services, and cast steel for export overseas.