管线钢氢致裂纹影响因素研究进展

RESEARCH PROGRESS OF INFLUENCING FACTORS OF HYDROGEN INDUCED CRACKING FOR PIPELINE STEEL

许多石油和天然气中都含有H2S,因此油气输送用管线钢应具备抗氢致裂纹（HIC）的性能.综述了化学成分、夹杂物及微观组织对管线钢氢致裂纹影响的最新研究进展.控制管线钢中C≤0.06％,Mn≤1.4％,同时使杂质元素P≤0.015％、S≤0.002％、O≤10 μg/g、H≤2.0 μg/g,并控制Ca为10～ 35 μg/g,从而减少长条状MnS夹杂、链状氧化铝B类夹杂及Mn、P偏析区,有助于提高管线钢HIC抗力.小尺寸及形态圆润无尖角夹杂周围不易形成HIC.管线钢采用针状铁素体组织,同时减少带状组织及MA岛数量及尺寸,可以在保证优异的强韧性同时,满足抗HIC性能要求.

Pipeline steels were widely used to carry natural gas and oil containing wet hydrogen sulphide,so it was necessary to improve Hydrogen Induced Cracking （HIC） resistance of the steels.Research progress concerning the influence of the composition,inclusions and microstructure of pipeline steel on HIC was discussed.The effect of chemical composition on HIC susceptibility could be limited by reducing sulfur to the maximum of 0.002％,phosphorus to the maximum of 0.015％,hydrogen to the maximum of 2.0 μg/g and oxygen to the maximum of 10 μg/g,controlling the carbon lower than 0.06％,manganese lower than 1.4％,and optimizing the addition of calcium for 10 ～35 μg/g,so as to reduce elongated MnS,clusters or stringers of oxides,centerline segregation and improve the HIC resistance.HIC did not nucleate around the inclusions with spherical shape and/or small size.The acicular ferrite microstructure with reducing banded structure and martensite/austenite （M/A） micro-constituent exhibited a good HIC resistant,in addition to the good mechanical properties of strength and toughness.