错边量对不锈钢中厚板K-TIG焊接头性能的影响

Effect of Misalignment on Properties of Thick Stainless Steel Plate K-TIG Welding Joint

开展了8 mm厚304不锈钢板K-TIG焊工艺试验,探索了错边量对接头性能的影响。结果表明:随着错边量增加,熔池形态扭曲程度加重,高位侧咬边不断增大;磁偏吹导致电弧热主要集中于焊缝区,焊缝及熔合区内奥氏体晶界处析出碳化物增多,热影响区内奥氏体粗化程度降低,硬化程度下降。接头薄弱环节由热影响区向焊缝区转移,抗拉性能及塑性也有所下降。然而,K-TIG焊对3 mm以内错边的适应性仍满足实际使用需求。

K-TIG welding process test of 304 stainless steel plate with 8 mm thickness was carried out. The effect of misalignment on the properties of joint was studied. The results show that with the increase of misalignment, the warping degree of molten pool morphology increases and the undercut of high side increases. The heat of arc due to magnetic bias blowing mainly concentrates in the weld zone. Carbide precipitation increases at austenite grain boundary in weld and fusion zone, and the austenite coarsening degree decreases, which leads to the decrease of hardening degree in HAZ. The weakness of joint transfers from HAZ to WZ(weld zone), tensile properties and plasticity of joint also reduce. However, the adaptability of K-TIG welding to misalignment within 3 mm still meets the practical requirements.