大型火电用改良型9Cr1Mo铸钢补焊工艺

大型9Cr1Mo铸钢件存在缩孔缩松等缺陷,需要进行补焊修复,在补焊时工艺处理不当,会再次形成危害性缺陷。为了消除铸件本身缺陷以及补焊后再次形成的缺陷,采用新的工艺进行补焊,结果表明,仔细清理缺陷和熔渣,待修复区域形状规则圆滑,严格控制预热及层间温度、首层及其它层补焊工艺参数,同时使用锤击松弛应力,并进行焊后热处理等措施可以很好消除改良型9Cr1Mo铸钢件的缺陷。

Repair welding technology of modified9Cr1Mo casting steel for large thermal power plant

Welding defects like shrinkage and cavity exist in large 9Cr1Mo steel casting, so repair welding is needed, improper repair welding process will lead to the formation of a dangerous defect again. In order to eliminate the casting defects and the defects induced by repairing, a new technology for repairing is adopted. Results show that the shape of the defect is regular and smooth, carefully clean up the defects and slag, strictly control preheating and interpass temperature, at the same time, using hammer for stress relaxation, strictly control the repair welding parameters of first layer and other layers, and in a timely manner with heat treatment after welding etc. can eliminate the defects effectively.