1.The test of sulphurized tufftride process for treating the hot piercing punch for steel pipes is introduced.

1.介绍了钢管热模硫氮碳共渗工艺试。

2.It is shown that the fracture properties are determined by materials strength before tufftride process and by materials toughness after tufftride process.

2.疲劳最后断裂性质取料的强度和韧性。