论文部分内容阅读
1 引言 在机械制造加工中,经常出现不合格品混在合格品中,使批量产品质量的可靠性下降。今年初我厂在生产军品任务中,发生了过热和轻度过烧零件混在合格品中,在加工时两件断裂。断裂件经过理化分析,材料化学成分正常25Cr_2Ni_4W,断口检查晶粒粗大,脆断,金相评极为00级特大晶粒。根据金属材料力学性能可知,零件组织晶粒粗大,金属的流变应力降低,
1 Introduction In the machinery manufacturing and processing, often appear unqualified mixed in qualified products, so that the reliability of bulk product quality declined. Earlier this year, I plant in the production of military tasks, overheating and light over-burning parts have been mixed in qualified products, processing two broken. Fracture after physical and chemical analysis, the chemical composition of the normal material 25Cr_2Ni_4W, fracture inspection coarse grains, brittle fracture, the metallographic review extremely 00 large grains. According to the mechanical properties of metallic materials, we can see that the coarse grains of the part structure, the flow stress of the metal is reduced,