During the manufacturing process of steel structures, some nodes intersect frequently, making welding inconvenient and causing high stress or inability to obtain the corresponding shape during welding. Therefore, nodes are indispensable in the use of large cast steel parts. The nodes of large cast steel parts are also a part of large cast steel parts. If the quality of the nodes is unqualified or defective, the use effect of the cast steel parts cannot be maximized, and the properties and quality of the product cannot be guaranteed very well.
Generally speaking, the heat treatment process for large cast steel joints is mainly divided into three stages: heating, insulation, and cooling. The selection of temperature and time for heat treatment is a key step in the casting of large-scale steel castings. The temperature time chart of heat treatment represents important data for monitoring the rationality of heat treatment. Heat treatment shall be carried out in accordance with the current national standard (Inspection Regulations for Heat Treatment of Steel Castings) KK/J-01-25-2002. The heat treatment methods for large cast steel joints include annealing, normalizing, and normalizing and tempering. The mechanical properties obtained by three different methods are different: usually, for large cast steel joints with less complex shapes and less thick walls, normalizing is sufficient. For large cast steel joints with complex shapes that are prone to deformation and cracking, annealing is preferred. Normalization and tempering are suitable for thick carbon steel castings and low alloy steel castings. The purpose of tempering is to eliminate stress in the joints of large cast steel parts, and to avoid deformation and cracking of the joints of large cast steel parts.
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.