X80级管线钢的抗氢致裂纹性能

Hydrogen induced crack-resistance of X80 pipeline steel

采用光学显微镜(OM)、扫描电镜(SEM)、能谱仪(EDS)、透射电子显微镜(TEM)等设备,运用电感耦合等离子体质谱(ICPMS)光谱分析技术和电子探针X射线显微分析技术,研究了3种不同合金体系X80级管线钢的抗氢致裂纹性能及氢致开裂(HIC)的原因。结果表明,新开发的两种低碳低锰微合金成分管线钢均满足X80级别钢的强度要求,其中加入较低锰的微合金体系试验钢经腐蚀溶液浸泡后没有裂纹出现,抗HIC性能较好。氢致裂纹主要沿着多边形铁素体边界扩展,针状铁素体具有一定的止裂作用。C、S、Mn、Si、Al等元素偏析造成的氧化物夹杂、富碳相及大块的MA岛不利于抗HIC性能。

Hydrogen induced crack-resistance properties of three alloy designed X80 pipeline steels and the reason for hydrogen induced cracking（ HIC） were investigated by optical microscopy（ OM）,scanning electron microscopy（ SEM）,energy dispersive spectroscopy（ EDS）,transmission electron microscopy（ TEM）,inductively coupled plasma mass spectrometry（ ICP-MS） technique and electron probe X-ray microanalysis. The results show that the strength of two kinds of newly developed low carbon and low manganese micro-alloyed steel meet the strength requirements of X80 grade steel,and after soaking in corrosive solution,the tested steel with lower manganese has no cracking and its HIC properties is better. Hydrogen induced cracking mainly extend along the border of polygonal ferrite and arrest by acicular ferrite. The oxide inclusions,carbon-rich phase and large MA island caused by C,S,Mn,Si,Al element segregation are not conducive to the HIC properties.