本文研究了碳对纯镍型铸铁焊条质量的三种作用:1.碳对热裂纹敏感性的作用;2.碳对气孔形成的作用;3.碳对焊缝金属收缩应力的作用。测定了焊缝金属的最佳含碳量,多于或少于该最佳含碳量均降低其抗热裂性能。随焊缝金属含碳量的增加,焊缝气孔及收缩应力随之减少。对有关上述现象的理由进行了讨论。 In this paper, three kinds of effects of carbon on the quality of pure nickel cast iron welding rod are studied: 1. the effect of carbon on the thermal cracking susceptibility; 2. the effect of carbon on the pore formation; 3. the effect of carbon on the shrinkage stress of the weld metal. The optimum carbon content of the weld metal was determined, and more or less than the optimum carbon content both reduced their hot cracking resistance. As the carbon content of the weld metal increases, the weld porosity and shrinkage stress decrease. The reasons for the above phenomenon are discussed.