不平衡因子对药芯焊丝CO2气体保护焊焊缝金属韧度的影响

Effect of unbalance factor on toghness of weld metal by CO2 arc welding with flux cored wire

关键词:  药芯焊丝  CO₂气体保护焊  韧度  不平衡因子

Key words:  flux cored wire  CO₂ arc welding  toghness  unbalance factor

摘要:

研究了由氮化物形成元素Al,Ti等控制的不平衡因子B对低合金药芯焊丝CO₂气体保护焊缝金属韧度的作用。结果表明,在药芯具有氧化性的条件下,不平衡因子B对焊缝金属韧度的作用仍然明显。并且相比实心焊丝CO₂气体保护焊而言,不平衡因子B的最佳值增大了。分析表明,药芯焊丝自身的氧化性是不平衡因子B增大的原因。在不平衡因子B由小增加到最佳值的过程中,焊缝金属组织由粒状贝氏体+板条铁素体逐渐向以夹杂物为核心的针状铁素体组织发展,由此其韧度逐渐改善;而当不平衡因子B超过最佳值较多时,过剩的氮化物形成元素进入铁素体固溶而导致脆化。

Abstract:

The effects of unbalance factor B controlled by nitride forming elements Al, Ti etc on the impact toghness of weld metal by CO₂ arcwelding with flux cored wire were studied.The experimental results showed that as theBincreases, the impact toghness increases at first and than deacreases.Because of the fluxes oxidability, the optimal value ofBraised as compared by CO₂ arc welding with solid wire.As the increases from the first to optimal value, the main microstructure of the weld metal changed from granular bainite and ferrite side-plate to acicular ferrite, so the impact toghness was improved.But in case of theBover the optimal value very much, the toghness deacreased because the surplus nitride forming elements resided in the parent of ferrite.