球铁铸件加工面焊补技术研究与应用

Research and Application of Welding Technology on Ductile Iron Casting Machined Surface

研究采用特殊焊补方式结合两阶段热处理工艺对球铁加工面孔洞类缺陷不良品进行焊补挽救处理,解决球铁焊补后因白口组织、硬度偏高引起的加工工序打刀、凸台、孔偏问题,降低铸造生产企业制造成本。研究结果表明,①采用冷悍焊条+氩弧焊焊补(电流230 A)焊补,采用(720~740)℃±10℃、(150~270)min±10 min、空冷的热处理工艺,热处理后焊点无白口组织,硬度均匀在160 HBW^217 HBW范围内,满足机加工要求。②采用(去除药皮)球铁焊条+氩弧焊焊补(电流230 A)焊补,采用(900~940)℃±10℃、(90.150)min±10 min、空冷和(720~740)℃±10℃、(150~270)min±10 min、空冷两阶段热处理工艺,热处理后无白口组织,硬度均匀在160 HBW^217 HBW范围内,满足机加工要求。

Special welding combined with two-stage heat treatment on the surface hole of ductile iron can save the castings, solve machining problems of cutter breakage,lug boss and eccentric hole caused by white tissue,high hardness after welding and reduce manufacturing costs. The results showed the cold welding electrode and argon arc welding repair （current 230 A） technology, and the heat treatment process of （720-740） ℃ ± 10 ℃, （150-270） min± 10 min and air-cooling made the welding spot without white and with uniform hardness of 160 HBW-217 HBW meet the machining requirements. The coating removed ductile iron electrode and argon arc welding repair （current 230 A） technology and two-stage heat treatment process of （900 - 940） ℃ ± 10 ℃, （90-150） min ± 10 min,air cooling and （720N740） ℃ ± 10 ℃, （150-270） min± 10 min,air-cooling made the welding spot without white and with uniform hardness of 160 HBW-217 HBW meet the machining requirements.