X80级管线钢硫化物应力腐蚀开裂研究  

Sulfide Stress Corrosion Cracking of X80 Pipeline Steel

作　　者：张鹏程[1] 唐荻[1] 武会宾[1] 黄国建[2] 王路兵[1] 谢广宇[1] 

机构地区：[1]北京科技大学高效轧制国家工程研究中心,北京100083 [2]鞍山钢铁集团公司技术中心,辽宁鞍山114001

出　　处：《材料保护》2008年第7期10-12,86,共3页Materials Protection

摘　　要：采用NACE三点弯曲方法,通过SEM、TEM等手段研究了两种成分的X80级管线钢的硫化物应力腐蚀开裂(SSCC)行为。腐蚀介质为CH3COOH(0.5%)+去离子水(99.5%)+通入饱和H2S气体(纯度99.9%以上),试验溶液温度保持在(25±3)℃,试验时间200h。结果表明,添加合金元素Cu,Ni的材料的临界应力值(Sc)超过1390MPa,而未添加Cu,Ni的材料的临界应力值仅为770MPa。添加合金元素Cu,Ni可以获得细小均匀的针状铁素体组织,大量晶粒承受氢压,可以显著提高材料的临界应力值(Sc),从而提高了材料抗SSCC的性能。针状铁素体内高密度缠结的位错和微合金元素的碳氮化物在位错网络上的沉淀析出,起到了强烈的氢陷阱作用,是针状铁素体具有良好抗SSCC性能的主要原因之一。NACE three-point standard bent-beam test was conducted to investigate the sulfide stress corrosion cracking(SSCC)of X80 grade pipeline steels with and without alloying elements.Thus the corrosion tests of the pipeline steel in aqueous solution of 0.5% CH3COOH saturated with H2S gas(purity above 99.9%)were carried out at a temperature of(25±3)℃ and for a duration of 200 h.Results indicated that the pipeline steel with Cu and Ni as micro-alloying elements had a critical stress of over 1390 MPa,while that without Cu and Ni registered a critical stress of only 770 MPa.The introduction of the Cu and Ni micro-alloying elements led to the formation of fine and uniform acicular ferrite microstructure and hence increased resistance to SSCC.Namely,in the pipeline steel with the micro-alloying elements,the hydrogen pressure was shared by more grains,leading to obviously increased critical stress and resistance to SSCC as well.Moreover,both the high density tangled dislocation and precipitation of carbonitrides of micro-alloying elements in dislocation networks played important roles as hydrogen entrappers,which was one of the main reasons for acicular ferrite to have excellent resistance to SSCC.

关 键 词：硫化物应力腐蚀开裂 管线钢 针状铁素体 

分 类 号：TG172.9[金属学及工艺—金属表面处理]