This review provided some recent progress of the research on corrosion mechanisms of magnesium and its alloys and a basis for follow-on research. Galvanic corrosion, pitting corrosion, intergranular corrosion (IGC), f...This review provided some recent progress of the research on corrosion mechanisms of magnesium and its alloys and a basis for follow-on research. Galvanic corrosion, pitting corrosion, intergranular corrosion (IGC), filiform corrosion, crevice corrosion, stress corrosion cracking (SCC), and corrosion fatigue (CF) were discussed. The influence of metallurgical factors such as alloying elements, microstructure and secondary phases, processing factors such as heat treatment and weld, and environmental factors including temperature, relative humidity, solution pH values and concentration on corrosion were discussed. In particular, a mechanism of pitting corrosion caused by AlMn particles was proposed. The corrosion properties of AZ91D weld material were investigated.展开更多
API SPEC5D标准规定的材料性能指标不能反映钻杆抵抗疲劳及腐蚀疲劳的性能。对4个厂家的S135钢级钻杆的材料进行了腐蚀疲劳寿命试验、拉伸性能试验及成分分析。试验结果表明,虽然4种钻杆的化学成分及材料性能都符合标准要求,且材料的拉...API SPEC5D标准规定的材料性能指标不能反映钻杆抵抗疲劳及腐蚀疲劳的性能。对4个厂家的S135钢级钻杆的材料进行了腐蚀疲劳寿命试验、拉伸性能试验及成分分析。试验结果表明,虽然4种钻杆的化学成分及材料性能都符合标准要求,且材料的拉伸强度基本相同,但腐蚀疲劳寿命相差很大。腐蚀疲劳断口观察及断裂机理分析表明,腐蚀疲劳裂纹扩展机理是阳极溶解与氢致开裂共存,氢致开裂加快了疲劳裂纹扩展。材料低倍组织酸洗检验、显微组织分析表明,4种钻杆的金属组织特别是低倍组织有明显差别。低倍组织反映了成分偏析程度、夹杂物含量及分布等。成分偏析及夹杂物导致材料的阳极溶解、特别是氢致开裂速度加快,所以是腐蚀疲劳寿命减少的主要原因。油田数据验证,钻杆材料的低倍组织酸洗检验可作为间接评定钻杆材料腐蚀疲劳性能的方法。展开更多
基金Project (CSTL, 2004BA4002 and 8655) supported by the Key Natural Science Foundation of Chongqing Municipal Science and Technology Committee, China Project (KJ050604) supported by the Science and Technology Program of Chongqing Municipal Education Committee, China
文摘This review provided some recent progress of the research on corrosion mechanisms of magnesium and its alloys and a basis for follow-on research. Galvanic corrosion, pitting corrosion, intergranular corrosion (IGC), filiform corrosion, crevice corrosion, stress corrosion cracking (SCC), and corrosion fatigue (CF) were discussed. The influence of metallurgical factors such as alloying elements, microstructure and secondary phases, processing factors such as heat treatment and weld, and environmental factors including temperature, relative humidity, solution pH values and concentration on corrosion were discussed. In particular, a mechanism of pitting corrosion caused by AlMn particles was proposed. The corrosion properties of AZ91D weld material were investigated.
