轧辊堆焊中显微组织对性能的影响

Effect of microstructure on properties of roll surfacing

轧辊堆焊层的使用寿命与堆焊合金表面硬度及堆焊质量密切相关,而表面硬度和堆焊合金组织密切相关。通过埋弧堆焊技术,以含高铬钼药芯焊丝为堆焊焊材,在45#钢基材上堆焊制备堆焊合金。420L焊丝堆焊合金层是由Fe-Cr固溶体和碳化物组成的树枝晶状组织,而YD255Mo-S焊丝堆焊合金层主要是由黑色针状马氏体和残余奥氏体混合物组成;两种焊丝堆焊的合金层的平均显微硬度分别为620HV0.2和634.6HV0.2,其最大误差分别为11.9%和9.1%。YD255Mo-S焊丝堆焊的合金层整体平均硬度值高且波动小。研究了两牌号的焊丝下形成的堆焊合金组织特征与合金表面硬度之间的关系。

The service life of roll surfacing layer is closely related to the surface hardness and quality of surfacing alloy,while the surface hardness is closely related to the microstructure of the surfacing alloy.The surfacing alloy was prepared on 45#steel substrate by the submerged arc surfacing technology using high-chromium molybdenum flux cored wire as the surfacing welding material.The alloy layer deposited by 420L welding wire had the dendritic structure composed of Fe-Cr solid solution and carbide,while the alloy layer deposited by YD255Mo-S welding wire was mainly composed of the mixture of black acicular martensite and residual austenite.The average microhardness HV0.2 of alloy layers deposited by two kinds of welding wires was 620 and 634.6,respectively.The maximum error was 11.9%and 9.1%,respectively.The overall average hardness value of alloy layer welded with YD255Mo-S wire was high with little fluctuation.The relationship between the microstructure characteristics of surfacing alloy formed under two grades of welding wire and the surface hardness of the alloy was studied.