为了研究Fe基、Cr3C2/Fe复合涂层的显微组织、抗高温氧化性能，以及Cr3C2/Fe复合涂层相结构演化规律，采用5kW CO2激光器在与Fe基合金成分相近的Q235钢表面熔覆Fe基合金涂层及Cr3C2/Fe基合金复合涂层的方法，进行了理论分析和实验验证，取得了相关试验数据。结果表明，Fe基合金涂层主要组成相为α-Fe，Cr23C6以及体心立方的α-Fe固溶体等；熔覆层主要以亚共晶方式结晶，在初生固溶体间存在层片状的共晶组织。Cr3C2/Fe基合金复合涂层组成为γ-Fe，α-Fe，Cr23C6，Cr3C2以及Cr7C3等。Fe基合金涂层由发达的α-Fe枝晶和其间共晶组织组成，Cr3C2/Fe基合金涂层典型组织为等轴晶以及细小的共晶组织；Cr3C2对熔覆层的组织有显著的改善作用，使其组织细化，促使组织由树枝晶向等轴晶转化；Cr3C2的加入可显著提高Fe基合金涂层的显微硬度、高温抗氧化性等物理性能。这一结果对以后相关的Fe基合金激光熔覆以及激光表面改性研究有一定的帮助。

In order to study microstructure, high temperature oxidation resistance of Fe-based, Cr3C2/Fe composite coating, as well as phase structure evolution of Cr3C2/Fe composite coating, Fe-based alloy and Cr3C2/Fe-based alloy composite coatings were obtained on Q235 whose composition is similar with Fe-based alloy with a 5kW CO2 laser. Then relevant test data were obtained and theoretical analysis was conducted. Results show that: the Fe-based alloy coating is mainly composed of phase α-Fe, Cr23C6, as well as the body-centered cubic α-Fe solid solution, etc.; the cladding layer mainly crystallizes in sub-eutectic crystallization way, there exists lamellar eutectic crystal organization between the primary solid solution. The main composition of Cr3C2/Fe-based alloy composite coating are γ-Fe, α-Fe, Cr23C6, Cr3C2 , Cr7C3 and so on. The Fe-based alloy coating is composed of well-developed α-Fe dendrites and the eutectic structure during the composition, Cr3C2/Fe-based alloy coating typical organizations are equiaxed grains, as well as small eutectic. Cr3C2 pairs play a major role in promoting the organization from dendrite to equiaxed transformation; Cr3C2 can significantly increase the micro-hardness, high temperature oxidation resistance and other physical properties of Fe-based alloy coating. The results have certain assistance for subsequent Fe-based alloy laser cladding and laser surface modification.