针对重型H型钢在纵向拉伸和Z向拉伸试验中塑性低和断口出现银白色斑点等异常现象,采用宏观观察、化学成分分析、金相检验、断口分析以及去氢退火试验等方法,对造成上述异常现象的原因进行了分析。结果表明:试样断口表面上存在的银白色斑点是氢不断地向试样材料缺陷处(氢陷阱)聚集而形成的“白点”。去氢退火可以有效地使恢复材料的塑性。

In view of the abnormal phenomena such as low plasticity and silvery white spots on the fracture of heavy type H-beam in longitudinal and Z-direction tensile tests. The causes of the above anomalies were analyzed by means of macroscopic observation, chemical composition analysis, metallographic testing, fracture analysis and dehydrogenation annealing test. The results show that the silvery white spots on the fracture surface of the sample were white spots formed by the continuous accumulation of hydrogen to the defects (hydrogen traps). Dehydrogenation annealing could effectively restore the plasticity of the material.