Analysis of the Stem-fillet blend fracture of exhaust valve was conducted by means of macroexamination, microstructure examination, chemical composition analysis and hardness test.

摘要采用宏、微观检验、化和硬度测试等方法对断头的排气门进行。

Research on the failure reasons of the cooling tube were carried out by means of macroexamination, thickness measurement, X ray diffraction, optical microscopy and chemical analysis.

采用宏、微观、化等手段,对冷却水管的腐蚀穿孔进行失效。