药芯焊丝冷裂敏感性研究

STUDY ON COLD CRACKING SUSCEPTIBILITY OF FLUX CORED WIRE

通过E70T -3、E71T -GS药芯焊丝焊缝金属中含氢量测定 ,熔敷金属化学成分分析 ,焊接热循环曲线测定 ,光镜和SEM微观分析 ,表明在拘束条件下 ,使用2 .4mmE70T -3药芯焊丝上坡、下坡短道焊焊接 16Mn和AISI10 10钢时 ,焊缝中产生低碳马氏体组织和高的扩散氢含量是诱导产生HIC的原因。在同样的条件下 ,采用E71T -GS药芯焊丝焊接时 ,焊缝金属中扩散氢含量低 ,微观组织未见马氏体组织 。

The amount of diffusion hydrogen of weld metal with E70T-3 and E71T-GS were measured separately. The chemical composition of weld metal was analyzed and the heat cycle curve of welding was measured. The microstructures of weld metal were also analyzed by the means of SEM and optical microscope. The results showed that the reasons of inducing HIC cracks were low carbon martensite structure and the higher amount of diffusion hydrogen in the E70T-3 weld metal when the joints of 16 Mn and AISI 1010 steel were welded with  2.4 mm E70T-3 flux cored wire by short weld length, slope up or slope down position welding under restrained condition. The amount of diffusion hydrogen in the weld metal was lower and there was no martensite microstructure in weld metal when the same kind of joints were welded with E71T-GS flux cored wire. Under the same restrained condition using E71T-GS flux cored wire, the weld metal possessed better ability to resist cold cracks.$$$$