焊接热输入量对铁基堆焊金属组织与性能的影响

Influence of welding heat input on Fe-based hardfacing metal's microstructure and properties

自行配制低合金钢药芯焊丝,并采用不同焊接热输入量制作相应的堆焊试样。采用金相显微镜对堆焊金属的显微组织进行观察;采用X射线衍射仪对堆焊金属的相结构进行分析;采用显微硬度计和砂带式摩擦磨损试验机对堆焊金属的硬度和耐磨性进行检测,并采用扫描电子显微镜观察堆焊金属的磨损表面及冲击断口。结果表明,在满足生产率的条件下,随着焊接热输入的降低,堆焊熔池温度逐渐降低,导致晶粒形核率升高而晶粒长大速度减慢,从而使堆焊金属晶粒逐渐细化。晶粒的细化直接影响到堆焊金属的宏观性能,使其硬度、耐磨性和冲击韧性均有所上升。

Preparing the low alloy steel flux cored wire and making welding specimen with different welding heat inpnt.Then observe the microstructure of welding metal with Metallographie microseope and analyze the metal phase structure with X ray diffraction,then test the hardness and wear resistance with micro hardness and wear and tear testing machine, and then observe the surface of wear and impact fracture with scanning electron microscope.The results show that .under the conditions meet productivity, with the decrease of welding heat input,the surfacing mohen pool temperature decreases,the rate of crystal grain incrases and the rate of crystal grain growth slows down.thus the metal crystal grain refinement.The refinement of the crystal grain improves the hardness,the wear resistance and impact toughness of the welding metal.