填粉率对复合粉粒和实心焊丝堆焊合金组织及耐磨性的影响  

Effect of powder addition ratio on the microstructure and abrasive wear resistance of hardfacing alloys deposited by composite powder particles and solid wire

作　　者：龚建勋[1] 姚惠文 程诗尧 刘超[1] 黄洪江 GONG Jianxun;YAO Huiwen;CHENG Shiyao;LIU Chao;HUANG Hongjiang(Xiangtan University,Xiangtan,411105,China)

机构地区：[1]湘潭大学,湘潭411105

出　　处：《焊接学报》2020年第7期53-58,I0003,I0004,共8页Transactions of The China Welding Institution

基　　金：湖南自然科学基金资助项目(2015JJ5031)。

摘　　要：粉末组分经干混、掺粘结剂湿混、旋转造粒、烧结和筛分等工序制备成10目~30目的复合粉粒,将之预置于焊道,以H08A实心焊丝为电弧载体,自保护明弧堆焊高铬合金.借助光学显微镜、X射线衍射仪、扫描电镜等方法,研究了填粉率对复合粉粒和实心焊丝堆焊合金组织及耐磨性的影响.结果表明,随着填粉率由30%提高至45%,该堆焊合金的显微组织由亚共晶转变为过共晶结构,主要基体由γ-Fe转变为α-Fe,M7C3相形态由沿晶断续网状或树枝状转变为颗粒状或块状.磨损试验结果表明,该方法堆焊的高铬合金耐磨性优良,与药芯焊丝堆焊高铬合金相当,制备工艺更为简便且经济,合金磨损机制包括磨粒的微切削和显微剥落两种形式.Composite powder particles with the size of 10-30 mesh were prepared by a series of processes including dry mixing,wet mixing with the addition of binding admixture,rotary pelleting,sintering and screen sizing on powder components.Those composite particles presetting on base metals were used as welding consumable together with solid wire which can be considered as arc carrier.High chromium alloys were deposited by the method of self-shielded open arc welding.The effects of powder addition ratio on the microstructure and abrasion resistance were investigated by optical microscopy(OM),X-ray diffraction(XRD)and scanning electron microscopy(SEM).The results indicate that,with powder addition ratio increases from 30%to 45%,the microstructure changes from the hypoeutectic to the hypereutectic.The dominant matrix converts changes from γ-Fe to α-Fe and the morphology of M7C3-type carbides transits from inter-granular reticular or dendritic shapes to granular or block-like ones.The results of wear test show that their abrasion resistance is excellent and corresponds to the one of flux-cored wire hardfacing alloys with such processing merits as simple and economic.The wear mechanism mode of hardfacing alloys includes micro-cutting and micro-spalling.

关 键 词：复合粉粒 实心焊丝 明弧 堆焊 高铬合金 

分 类 号：TG422.1[金属学及工艺—焊接]