冷轧对DT4管材化学镀Ni-P合金层性能的影响

Effect of cold rolling on properties of electroless deposition Ni-P coatings on DT4 pipes

为适应DT4工业纯铁管材使用过程中要求高的耐蚀性,对经氩弧焊焊接、冷轧成形并多次退火的DT4管材表面进行化学镀镍磷处理,并通过对镀层再次冷轧变形以改善镀层性能。结果表明,退火处理减少了DT4管材的焊接缺陷和残余应力,为化学镀Ni-P合金提供良好的基体;镀层经冷轧变形后孔隙率降低,改善了与基体的结合力,提高了耐蚀性。

DT4 pure iron pipe was prepared by argon arc welding and cold rolling,and then annealing for several times.To achieve high corrosion resistance for DT4 pure iron pipe in service,electroless nickel phosphorous plating was performed on the surface,and cold rolling was carried out once more to improve the properties of the Ni-P coatings.The results indicat that annealing process reduces the weld defects and residual stress of DT4 pipes,and provides favorable substrate for the electroless plating.The additional cold rolling decreases the porosity of the coating and increases the adhesion of the coatings to the substrate plane,and hence improves the corrosion resistance.