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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 new type of wear-resistant flux cored wire developed by ourselves. The Ghost-3500 thermal simulation tester was used to simulate the coarse-grained intergranular structure of the deposited metal at 19.5, 25, 39 and 50 kJ / cm. The microstructure and properties of the simulated coarse grains were studied by impact test, metallographic observation, hardness test and sliding wear test. The results show that as the energy of the wire increases, the grains in the simulated coarse grain area increase, the precipitates increase, and the Paralympic decrease, the microstructure is martensite + carbide + Paralympic. When the energy of the line is 50 kJ / cm When the granular bainite appears. Under the four kinds of line energy, the impact energy of NM12 wire deposited metal simulation coarse grain area is very low. The hardness of the sample in the simulated coarse grain region increased slightly with the increase of the line energy. The wear resistance increased slightly and then decreased slightly with the increase of the line energy. The wear amount was the least when the line energy was 25 kJ / cm. The research shows that the energy of the wire has little effect on the performance of the simulated grain area of the deposited metal of the NM12 wire, and the wire can be applied to the large wire energy of the double wire submerged arc welding.