埋弧药芯焊丝Nb、V合金元素含量对堆焊熔敷金属耐腐蚀性能的影响

Effect of Nb and V Alloying Element Content of Submerged Arc Flux Cored Wire on the Corrosion Resistance of the Surfacing Deposited Metal

1Cr13马氏体不锈钢常用于制造冶金轧辊、汽轮机叶片、泵轴等零件,这些零件因腐蚀产生的表面微缺陷常导致零件断裂失效,向堆焊熔敷金属中过渡适量特定合金元素,可有效改善其耐腐蚀性能。文中在1Cr13药芯焊丝配方的基础上,通过添加不同含量的铌铁和钒铁(3.2 wt.%、6 wt.%、10 wt.%)制备了三种埋弧药芯焊丝进行堆焊试验,分析堆焊熔敷金属的显微组织,并研究Nb、V含量对堆焊熔敷金属耐腐蚀性能的影响。结果表明,随着药芯焊丝中铌铁和钒铁含量的增加,堆焊熔敷金属中析出相的数量逐渐增多,这些析出相为含Nb、V的碳氮化物,能有效抑制富Cr析出相的形成,提高基体中的有效Cr含量;大量均匀分布的析出相有利于腐蚀从多位置发生,促进了堆焊熔敷金属的均匀腐蚀,改善了堆焊熔敷金属的耐腐蚀性能。但含Nb和V的析出相过度析出会使基体中大量C、N原子脱溶,导致堆焊熔敷金属硬度下降。

1Cr13 martensitic stainless steel is commonly used in the manufacture of metallurgical rolls,turbine blades,pump shafts and other parts,which often fail due to fracture of the parts as a result of surface micro-defects generated by corrosion,and the appropriate addition of alloying elements that transition to the overlay layer metal can effectively improve their corrosion resistance.In this paper,on the basis of the 1Cr13 flux cored wire formulation,three types of submerged arc flux cored wires were prepared by adding different contents of iron niobium and iron vanadium(3.2 wt.%,6 wt.%,10 wt.%).Cladding tests were carried out to analyse the microstructure of the cladding layer metal and to study the effect of Nb and V content on the corrosion resistance of the clad metal.The results show that with the increase in the content of iron niobium and iron vanadium in the flux-cored wire,the number of precipitated phases in the overlay metal gradually increases,and these precipitated phases are carbon and nitride containing Nb and V,which can effectively inhibit the formation of Cr-rich precipitated phases and improve the effective Cr content in the matrix;a large number of uniformly distributed precipitated phases are conducive to corrosion from multiple locations,which promotes the uniform corrosion of the surfacing deposited metal and improves the corrosion resistance of the deposited metal The corrosion resistance of the metal is improved.However,the excessive precipitation of the Nb and V phases will cause a large number of C and N atoms in the matrix to be desolvated,resulting in the decrease of hardness of surfacing deposited metal.