本文对用GCr15精铸的钴、镗床“菱形块”,增力夹紧机构零件进行的受力分析及脆断故障的失效分析作了全面论述。介绍了选材研究过程,指出:研制成功的新钢种ZG50CrMnVRE(稀土)在常规力学性能、小能量多次冲击弯曲抗力、断裂韧性、耐磨性能、淬透性、铸造性能、实物单冲及抗压溃性、脱碳倾向、动态模拟使用性试验等许多方面均优于GCr15。 In this paper, GCr15 cast cobalt, boring machine “diamond block”, force clamping mechanism parts of the force analysis and failure analysis of brittle failure were comprehensively discussed. The research process of material selection is introduced. It is pointed out that the new type of steel ZG50CrMnVRE (rare earth) successfully developed has good performance in conventional mechanical properties, small impact resistance, fracture toughness, wear resistance, hardenability, casting property, Crush, decarburization tendency, dynamic simulation usability test and many other aspects are better than GCr15.