球墨铸铁QT500-7电弧冷焊工艺研究

Cold Welded Process of A QT500-7 Type Spheroidal Graphite Cast Iron

利用火焰喷焊和手工涂敷两种方法在球墨铸铁表面预置镍基合金过渡层,后采用镍铁焊条大电流连续焊接 分析了镍基合金过渡层与母材的结合情况和焊接接头的金相组织及硬度分布,结果表明:过渡层与母材结合良好,喷焊过渡层的焊接接头热影响区基本无白口及淬硬组织,接头宏观硬度低于HB210,可满足机加工要求。

Via flame spraying and manual spreading, nickel alloy transitional plate was preset on the surface of QT500-7type spheroidal graphite cast iron, which was then welded continuously under high current using ferronickel electrons. The welds of the nickel alloy transitional plate and the base metal were examined and analysed for their microstructures and hardness of . The results showed that the transitional plate and base metal are jointed quite well with no white or hardening structure on the nickel alloy transitional plate. The hardness of the joints was less than HB210, which meet the requirement of cold machining. It can be concluded that the presetting nickel alloy transitional plate can be a feasible method for spheroidal graphite cast iron repair.