稀土元素对自保护药芯焊丝的影响

摘要

研究了三种稀土合金及混合稀土对自保护药芯焊丝熔敷金属中含氧量、含氮量、气孔敏感性的影响规律，通过试验及理论分析发现，增加稀土元素的添加量，可使熔敷金属中含氧量下降，降低了气孔敏感性，混合稀土的作用最明显，它完全抑制了气孔。而由于稀土元素在先期脱氧中大量氧化，其脱氮效果较弱，稀土元素对熔敷金属的总含氮量的影响不显著。但通过稀土的固氮作用可使总含氮量控制在一定的范围内，并降低了氮的有害作用。适量的稀土元素可改善焊缝金属组织的形态、细化晶粒、提高韧性。%The influence of three kinds of Re elements and Re metal mixture on the oxygen,nitrogen content and proe sensitivity in the weld of self-shielded flux-cored wire was investigated in the present study.Significant findings of this study revealed that the oxygen content and pore sensitivity in the weld were reduced with the increase of Re element addition,among which the Re metal mixture most effectively depressed the formationof porosity.The effect of Re element addition on the nitrogen content in the weld was insignificant due to the oxidization from the early deoxidization stage.However,the Re elements could effectively fix the nitrogen so that the nitrogen content in the weld could be controlled to certain beneficial ranges.It was also found out that proper Re element addition could increase the toughness of the weld metal and improve its microstructure by grain refinement.