The picture shows a batch of grate bars produced in January 2019. The main size is 343*41.5*37mm, which is made of silica sol precision casting. Its material 1.4740 is organized as a ferrite matrix, and the characteristics are as follows:
High carbon: 0.3-0.5%, to ensure excellent mechanical properties of the material;
High silicon: 1-2.5%, improve the high temperature performance of castings;
High chromium: 16-19%, improve the corrosion resistance of the material;
1.4740 material has high hardness (as-cast hardness: about 500HBW); no phase change occurs during heat treatment, mainly to improve the distribution of carbides; at the same time, it is necessary to avoid the embrittlement temperature of 475 ℃ to prevent brittle cracking of the casting.