中文摘要：

针对690 MPa级海洋平台用钢采用编号为690-H手工电弧焊条进行焊接,应用光谱分析法、Lepera试剂腐蚀法以及光学金相显微镜观察分析,对熔敷金属的性能进行了研究。分析了合金元素、M-A组元的形态对熔敷金属性能的影响。结果表明采用690-H焊条焊接时,690 MPa级海洋平台用钢低温力学性能符合要求,但还需做如下改进应适当降低焊缝金属Cr、Mo、Si含量,提高Ni含量及适当快冷以减少块状M-A组元数量,从而进一步改善焊缝金属的硬度,提高其低温韧性。

英文摘要：

One smaw welding rod（690-H）was developed for 690 MPa grade off-shore platform plate steel. The properties of deposited metal was researched by optical spectrum,Lepera reagent, and optical microscope. The alloy elements, pattern of M-A constituents were studied. The results show that the mechanical property of low temperature of 690 MPa grade off-shore platform plate steel can satisfy the performance requirements by using 690-H. The weld metal hardness and low temperature toughness improve by reducing the metal content of Cr,Mo,Si, increasing Ni and rapidly cooling to reduce the number of massive M-A constituents.