核级气保焊丝ERNiCrFe-7A的研制

Development of Nuclear Grade Gas Shielded Welding Wire ERNiCrFe-7A

ERNiCrFe-7A焊丝被广泛应用于核岛主设备的制造和安装,但目前此类焊材基本依赖进口。本文介绍研制的一种符合ERNiCrFe-7A标准的镍基合金焊丝,并对其焊接工艺性、焊缝金属的力学性能及微观组织进行了分析研究。结果表明:研制的焊丝焊接工艺性良好,焊道成型平整;焊缝金属在焊态和焊后热处理态下均具有较高的强度和良好的塑性,强度、伸长率、冲击功等力学性能均满足在核电工程上的安全应用条件;熔敷金属组织多为柱状晶,在晶界和晶内存在以碳化物为主的析出相,析出相形貌为不规则的块状,尺寸集中在1~5μm。

ERNiCrFe-7A wire is widely used in the manufacture and installation of nuclear power main equipment,but this welding material is basically dependent on imports.A nickel base alloy welding wire was developed which meets the standare of ERNiCrFe-7A,and the weldability of the welding wire,mechanical properties and microstructure of the weld metal were studied.The results show that the welding wire has good weldability,the weld forming is smooth and tidy;the weld metals in welded and heat treated states have high strength and good plasticity,and the strength,elongation,impact energy and other mechanical properties satisfy the safty application requirement in nuclear power engineering;the microstructure of the weld metal is columnar crystal,and the precipitated phase is mainly carbides,which is distributed at grain boundaries and grains,the morphology of the precipitated phase is irregular clumps with size of 1-5 μm.