CaCO_(3)对复合粉粒和实心焊丝明弧堆焊高铬合金组织及耐磨性的影响  

Effects of CaCO_(3)on the Microstructure and Abrasion Resistance of High Chromium Alloys Deposited by Open Arc Welding with Composite Powder Particles and Solid Wire

作　　者：龚建勋[1] 刘超[1] 黄洪江 艾孝文 刘书同 GONG Jian-xun;LIU Chao;HUANG Hong-jiang;AI Xiao-wen;LIU Shu-tong(School of Mechanical Engineering and Mechanics,Xiangtan University,Hunan Xiangtan 411105,China)

机构地区：[1]湘潭大学机械工程和力学学院,湖南湘潭411105

出　　处：《表面技术》2023年第2期215-224,共10页Surface Technology

基　　金：湖南省自然科学基金(2021JJ30669)。

摘　　要：目的将活性剂引入复合粉粒,旨在改变电弧对其的作用属性,以提高堆焊金属的合金化元素量,从而改善其耐磨性。方法以复合粉粒和实心焊丝作为填充材料,采用自保护明弧焊法制备系列高铬合金。借助X射线衍射仪、扫描电镜及附属电子能谱仪等手段,研究复合粉粒添加CaCO_(3)含量对其堆焊高铬合金的组织及耐磨性的影响。结果随着CaCO_(3)添加量增大,焊缝的碗形熔深随之消除,堆焊合金的粉粒填充量由43.7%提高到47.5%,熔合比由0.281降低至0.140。这使堆焊合金组织由亚共晶变为过共晶结构,初生M7C3相的体积分数随之明显增加,堆焊合金硬度从55.4HRC提高至62.3HRC,磨损质量损失从54.9mg降低至16.7mg,耐磨性净增加2.3倍,合金磨损方式包括微观切削和显微剥落。高速摄影仪所拍电弧影像和电流电压数据显示,复合粉粒添加CaCO_(3)粉,使其堆焊电弧形态从圆锥形转变变为扁平钟罩形,电弧覆盖面积扩展约2倍。结论复合粉粒引入CaCO_(3)粉,促使电弧扩展,这不仅提高了复合粉粒的熔化量,而且显著降低了母材的稀释作用,以微小成本而显著改善了合金组织及耐磨性。The work aims to introduce activating flux into the composite powder particles(CPPs)to change the arc behavior on CPPs and increase the content of alloying elements in hardfacing metals,so as to improve their abrasion resistance.Five groups of high chromium alloys were deposited by self-shielded open arc welding with filler materials such as CPPs and H08A solid wire.Then,the effects of different CaCO_(3)contents on the arc shape,arc stability,microstructure,and abrasion resistance of high-chromium hardfacing alloys were investigated in detail.Q235 mild steel plates with the dimension of 180 mm×52 mm×10 mm were selected as the base metals.The CPPs were evenly placed in the middle of the weld beads.H08A solid wire was used as the self-consuming electrode and self-shielded open-arc welding was performed with a ZD5-1000E DC welder set with reverse polarity.Hardfacing samples with two layers were deposited with the same process parameters.HR-150 Rockwell hardness tester was used to test the bulk hardness values of these hardfacing specimens,and the average value of 10 readings was used as the final data.A metallographic specimen with the dimension of 12 mm×10 mm×30 mm was prepared by wire electrical discharge machining(EDM).The un-etched metallographic specimens were firstly used to analyze the phase compositions via D/MAX2550VB X-ray diffractometer(XRD).Then,these specimens were etched with 4%nitric acid alcohol and observed with VHX-2000C three-dimensional super-field depth microscope.The carbide morphologies were observed by a JSM-6360LV scanning electron microscope(SEM)and the micro-area compositions were analyzed by an attached Oxford7854 energy dispersive spectrometer(EDS).HV-1000 micro-Vickers hardness tester was used to measure the micro-hardness values of the specific phases.MLS-225 wet sand rubber wheel type abrasion tester was used to test abrasion resistance.High-speed synchronous camera and AcutEye V4.0 welding current and voltage sensors were used to capture the arc image and record current and volta

关 键 词：复合粉粒 明弧 堆焊 高铬合金 活性剂 碳酸钙 耐磨性 

分 类 号：TG422.1[金属学及工艺—焊接]