高强度低合金结构钢焊缝与母材的强度匹配研究

Investigation of strength matching of high strength low alloy steel and its weld metal

焊缝金属与母材的强度匹配系数是焊接接头力学性能非均匀参数之一,匹配方式不仅取决于焊缝金属和母材的名义强度,还取决于它们的分布形式和特征参数。试验和统计计算结果表明,12Ni3CrMoV钢和10Ni5CrMoV钢母材和焊缝金属的抗拉强度都服从正态分布。12Ni3CrMoV钢和其焊缝金属的强度匹配属于低强匹配,其低强、等强和超强匹配的概率分别为59.33%,37.03%和3.64%,低强匹配特征明显。10Ni5CrMoV钢和其焊缝金属的强度匹配属于等强匹配,其低强、等强和超强匹配概率分别为47%,48%和5%,其等强匹配概率分布比较明显。对应的两种钢的焊接接头,其超强匹配概率分别为3.64%和5%,在结构、焊接材料、工艺设计中值得注意。由于强度匹配系数的随机性,如何确定强度匹配系数、在什么范围内分别属于超强、等强、低强匹配,特别是等强匹配的界定方式应有别于低强和超强匹配,都是有待研究的问题。

The strength matching coefficient is one of the non-uniform parameters of mechanical performance of welded joint.The matching form is not only determined by the design strength of base metal and weld metal,but also concerned with their strength distribution and distribution parameters.As for12Ni3CrMoV steel,10Ni5CrMoV steel and their weld metals,the results show that:the tensile strength of both base metal and weld metal of the two steels obey the normal distribution.The nominal matching form of12Ni3CrMoV steel and its weld metal is under match.As the probabilities of under match,equal match and over match are59.33%,37.03%and3.64%respectively,the under match characteristic is prominent.The nominal matching form of10Ni5CrMoV steel and its weld metal is equal match.As the probabilities of under match,equal match and over match are47%,48%and5%respectively,the equal match characteristic is prominent.To both steels,the over match probabilities are3.64%and5%respectively and that should be noticed in welding structure design,welding material selection,as well as procedure design.Because of the randomness,how to identify the ranges of strength matching coefficient,which belongs to over match,equal match and under match,is a problem to be solved.