提高汽车车身电阻焊电极屈服强度的研究

Study on Increasing the Yield Strength of Autobody Resistance Welding Electrode

研究了电阻焊电极合金经 93K低温处理后晶粒细化对高温屈服强度的影响。研究结果表明 :增加单位体积的晶界数量 ,即增加单位体积的晶界能 ,能提高电极合金的塑性变形阻力。电极承载时 ,近似平面应变 ,符合Brinell硬度试验的HB Y≈ 2 .8～ 2 .9关系式。单位体积内晶界数量增多 ,意味着合金固溶体在切应力作用下滑移阻力增大 。

The influence of resistance welding electrode alloy's grain refined after 93K cryogenic treatment to high temperature yield strength is studied in this paper . Study result indicates : adding the crystal boundary amount of unit volume , i.e. adding the crystal boundary energy of unit volume , can increase plastic deformation resistance of electrode alloy . When electrode is loaded , it approximates to plane strain and accords with the Brinell hardness test's relational expression(HB/Y≈2.8～2.9). The addition of crystal boundary amount in unit volume predicates alloy solid solution's slip resistance added by the action of shearing stress . It can explain with Hall—Patch relational expression(σ s=σ 0+K yd -1/2).