线能量对NM12焊丝熔敷金属道间粗晶区性能的影响  

Effect of Heat Input on Properties of Coarse Grained Zone between Weld Beads in Wire NM12 Deposited Metal

作　　者：柯鑫[1] 陈冰泉[1] 卢伟 黄永溪 汤剑[1] 

机构地区：[1]武汉理工大学华夏学院,湖北武汉430223 [2]武汉铁锚焊接材料股份有限公司,湖北武汉430084 [3]中钢邢台机械轧辊有限公司修复公司,河北邢台054025

出　　处：《热加工工艺》2016年第11期197-199,203,共4页Hot Working Technology

摘　　要：NM12是自行研制的一种新型耐磨药芯焊丝。利用Gleeble3500热模拟试验机模拟了该焊丝熔敷金属在19.5、25、39、50 k J/cm四种线能量下的道间粗晶区组织。通过冲击试验、金相观察、硬度试验和滑动磨损试验对模拟粗晶区的组织和性能进行了研究。结果显示:随着线能量的增大,模拟粗晶区的晶粒增大,析出物增多,残奥减少,组织为马氏体+碳化物+残奥;当线能量为50 k J/cm时,出现粒状贝氏体。在四种线能量下NM12焊丝熔敷金属模拟粗晶区的冲击功都很低。模拟粗晶区试样的硬度随线能量的增加而略有增加,耐磨性能随着线能量的增加先提高后小幅降低,线能量为25 k J/cm时磨损量最小。研究认为,线能量对NM12焊丝熔敷金属模拟粗晶区性能的影响不大,该焊丝可应用于双丝埋弧焊的大线能量下。NM12 is a self-developed new abrasion resistant flux-cored wire. With the aid of thermal simulation testing machine Gleeble3500, the microstructure in the coarse grained region between weld beads of NM12 deposited metal at19.5k J/cm、25k J/cm、39k J/cm、50k J/cm four types of heat input was simulated. By means of impact test, metallographic observation, hardness test and sliding wear test, the properties and microstructure in the simulated coarse grained region were studied. It is showed that： the grain of simulated coarse grained region grows, precipitates increase and retained austenite decreases with the heat input increasing, and the microstructure of this zone is mainly martensite ＋retained austenite ＋carbide.And there is granular bainite when heat input reaches 50 k J/cm. All impact work of the simulated coarse grained region of NM12 wire deposited metal is very low under four kinds of heat input. Hardness of the simulated coarse grained region slightly increases with heat input increasing. Wear-resisting property increases firstly and then decreases slightly with heat input increasing, and wearing value is the lowest as heat input is 25 k J/cm. It can be considered that the influence of heat input on properties of the simulated coarse grained region of NM12 wire deposited metal is not obvious,this wire can be used for high heat input condition as double wires submerged arc welding.

关 键 词：线能量 NM12耐磨药芯焊丝 粗晶区 热模拟 

分 类 号：TG422.3[金属学及工艺—焊接]