堆焊35CrMo钢连接层的组织和性能

Microstructure and properties of 35CrMo steel joint layer

采用Ar气体保护焊的焊接方法,选择“基体+过渡层+保护层”的结构,首先在35CrMo钢上堆焊ER83-1的低合金钢焊丝的过渡层,随后在过渡层上堆焊HS112耐磨钢焊丝的保护层,焊接电流为300 A,焊接电压为25 V,焊接速度为7 mm/s,气体流量为18 L·min^(-1),并选择左向焊的焊接方法,以获得连接质量较好的焊接连接层。对过渡层、保护层进行了显微组织、硬度及拉伸性能的分析,结果表明,在基体和过渡层的连接层中,铁素体薄层和珠光体以长块状形态交替分布,这种弥散分布的形式有利于改善过渡层的塑韧性;而过渡层+保护层由细针状铁素体、少量块状铁素体以及珠光体组成,此时保护层的硬度在47~49HRC范围内,而抗拉强度达到了765.8 MPa。

The structure of"matrix+transition layer+protective layer"was fabricated by Ar gas shielded welding.Firstly,the transition layer of ER83-1 low alloy steel wire was overlaid on 35 CrMo steel,and then the protective layer of HS112 wear resistant steel wire was overlaid on the transition layer.The welding current was 300 A,the welding voltage was 25 V,the welding speed was 7 mm/s,and the gas flow rate was 18(L·min^(-1)),The welding method of left welding was selected to obtain the better bonding performance and weld the bonding layer.The microstructure,hardness and mechanical properties of the transition layer and protective layer were analyzed.The results showed that the ferrite thin layer and pearlite alternately distributed in the form of non-lamellar shape in the connecting layer between the matrix and the transition layer,which was helpful to improve the plasticity and toughness of the transition layer.The hardness of the protective layer was in the range of 47~49 HRC,and the tensile strength was 765.8 MPa.