本文详细介绍了对美国BJ公司MAA-250型吊卡的解剖分析结果。该型吊卡主体为低碳Ni-Cr-Mo系合金铸钢,相当于ASTM A732 9Q铸钢,其金相组织为回火索氏体和回火屈氏体的混合组织。钢材的淬透性较高,冷脆倾向较低,缺口敏感度小。该型吊卡主体及其他各零件的选材和工艺应用,还体现了“等强度设计”思想。 This article describes in detail the anatomical analysis of the American BJ MAA-250 elevator. The main body of the elevator is a low-carbon Ni-Cr-Mo alloy cast steel, which is equivalent to ASTM A732 9Q cast steel. Its microstructure is a mixed structure of tempered sorbite and tempered troostite. High hardenability of steel, cold brittle tend to lower the gap sensitivity. The Elevators body and other parts of the selection and application of technology, but also reflects the “strength design” thinking.