一、引言 铸铁焊修技术在工业、农业、国防工业中应用很广,如铸造缺陷的焊补、损坏零件的焊修等,有很高的经济效益和社会效益,被国家经委、国家计委列为“七五”、“八五”期间重点推广项目。铸铁的焊接性能很差,在焊接过程中易出现白口及淬硬组织,易产生裂纹,易出现夹渣和气孔,难以熔合,因此曾一度被认为是焊接“禁区”。铸铁焊接技术难度大且该领域存在高级技术人才严重不足的问题,给这项技术的普及和推 I. INTRODUCTION Cast iron welding repair technology is widely used in industry, agriculture and national defense industry, such as welding repair of casting defects, welding repair of damaged parts, etc. It has high economic and social benefits. It has been widely applied by State Economic Commission, State Planning Commission As a “seven five”, “eight five” during the promotion of key projects. Cast iron welding performance is poor, prone to white and hardened tissue in the welding process, easy to produce cracks, easy to slag and porosity, difficult to fusion, it was once considered welding “forbidden zone.” Cast iron welding technology is difficult and there is a serious shortage of senior technical personnel in this area, the popularity of this technology and push