激光熔覆用高硬度铁基合金的研究与应用

研究了激光熔覆Fe-Ni-Cr—B—Si合金粉末时粉末中的碳含量对于熔覆层组织、开裂敏感性、硬度和硬度均匀性的影响。结果表明，粉末含碳量的微小变化能显著改变熔覆层的组织和性能；在相同工艺条件下，粉末含碳量在一定范围内可显著提高熔覆层的硬度、降低熔覆层开裂敏感性，从而获得高硬度无裂纹的熔覆层；碳含量的增加可提高熔覆层的硬度均匀性。本文还报道了用自制Fe基合金粉末成功修复大型轧辊的实例。

Development and Application of High Hardness Fe-Based Alloy for Laser Cladding

The effects of carbon content on the microstructure,cracking sensibility,hardness and hardness uniformity of Fe-Ni-Cr-B-Si alloy powders laser-clad layers was studied.The results show that the small change of the carbon content in the alloy powders can obviously change the microstructure and properties of the layers.Under the same process parameters,the carbon content over a suitable range in alloy powders can obviously increase the hardness of the layers and decrease the cracking susceptibility of them.As a result,crack-free coatings with high hardness can be obtained.The hardness uniformity of the layers is improved by increasing of the carbon content.As a practical example,a large mill roll has been successfully repaired with the self-made Fe-based alloy powders