Nodular cast iron shows poor weldability due to obvious crack tendency caused by chilled structure in interface region during welding and cladding process. However, chilled structure could be eliminated by controlling interface heat input during laser cladding process. In this paper, brazing interface characteristic with no chilled structure could be obtained by controlling the heat input of the interface, and the results showed that the brazing interface illustrated higher strength compared with the chilled structure interface. The results illustrated that the tensile strength of specimens with brazing and intermittent chilled structure characteristic could reach 564 MPa. However, tensile strength of specimens with continuous chilled structure characteristic was lower than 353 MPa. Cracks formed in the interface zone and extended to the ledeburite region. FEM method with the help of ANSYS software was adopted to determine the thermal cycles of the interface region during the cladding process, and the mechanism of the interface behavior was studied.

球墨铸铁由于在焊接和熔覆过程中界面区域的冷硬组织引起的明显裂纹倾向而显示出较差的可焊性。但是，可以通过控制激光熔覆过程中的界面热量输入来消除冷却结构。通过控制界面的热量输入，可以获得无冷硬结构的钎焊界面特性，结果表明，与冷硬结构界面相比，钎焊界面具有更高的强度。结果表明，具有钎焊和断续冷态结构特征的试样的拉伸强度可以达到564 MPa。但是，具有连续冷却结构特征的试样的拉伸强度低于353MPa。裂纹在界面区域形成并延伸到莱德贝特区域。采用有限元方法，借助ANSYS软件确定包层过程中界面区域的热循环，研究了界面行为的机理。