深冷处理提高镀锌钢板点焊电极寿命的机理

为了提高镀锌钢板点焊电极寿命，作者提出了镀锌钢板点焊电极的深冷处理方法。采用不同深冷处理工艺参数处理了点焊镀锌钢板的Cr—Zr—Cu合金电极，用这些电极进行了镀锌钢板点焊电极寿命试验并与未深冷处理的电极寿命进行了比较。用扫描电子显微镜对深冷处理电极进行了背散射及面扫描分析，用X射线衍射法观测了深冷处理前后的电极晶粒度，测试了电极在深冷处理前后的电阻率。通过对深冷电极微观结构的观测及电极性能的测试，探讨了深冷处理提高镀锌钢板点焊电极寿命的机理。研究结果表明，深冷处理提高了镀锌钢板点焊电极基体的致密性，改变了合金元素的分布，细化了电极材料的晶粒，提高了镀锌钢板点焊电极的导电、导热能力及电极抗压渍变形的能力，从而提高了镀锌钢板点焊电极的寿命。

Mechanism of cryogenic treatment improving electrode life for spot welding zinc-coated steel sheet

In this paper,to improve electrode life of resistance spot welding of hot dip galvanized steel sheet,the way of deep cryogenic treatment of electrodes is put forward.Electrodes for spot welding are treated by deep cryogenic treatment with different deep cryogenic treatment parameters.Deep cryogenic treatment electrodes life experiment is carried out and the experiment results are compared with the non deep cryogenic treatment electrodes life experiment ones.The electrical conductivities of the deep cryogenic treatment electrodes and the non deep cryogenic treatment electrodes are tested.The SEM area scanning and the SEM back scattering of the electrodes are carried out.The grain degree of deep cryogenic treatment electrodes and the non deep cryogenic treatment electrodes are observed by X Ray Diffraction.The mechanism of cryogenic treatment improving electrode life for resistance spot welding of hot dip galvanized steel plate is summarized.The experimental results show that deep cryogenic treatment makes Cr,Zr in deep cryogenic treatment electrodes emanate dispersedly and makes the grain of deep cryogenic treatment electrodes smaller than non cryogenic treatment ones,so that the electrical conductivity and the thermal conductivity of deep cryogenic treatment electrodes are improved very much ,which make electrode life for spot welding hot dip galvanized steel sheet improve obviously.