硬面合金中碳氮析出物的研究-《郑州大学学报(工学版)》

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作者:: 杨可; 余圣甫; 陶潘峰; 等.; 华中科技大学,材料科学与工程学院,湖北,武汉,430074, 华中科技大学,材料科学与工程学院,湖北,武汉,430074, 华中科技大学,材料科学与工程学院,湖北,武汉,430074, 华中科技大学,材料科学与工程学院,湖北,武汉,430074, 华中科技大学,材料科学与工程学院,湖北,武汉,430074

摘要:: 硬面合金是利用研制的氮合金自保护硬面药芯焊丝在低碳钢板上堆焊得到.Nb和Ti作为最有效的碳氮合金化元素被加入到硬面合金中.用光学显微镜、扫描电镜、电子探针研究了硬面合金中碳氮析出物形态和组成,并进行了热力学分析,讨论了碳氮析出物对组织的影响.结果表明:硬面合金中的碳氮析出物为分布在晶界和位错上的MX(M＝合金元素,X＝C、N)复合型碳氮化物,焊态和热处理条件下具有不同的数量和尺寸.初生碳氮析出物在焊缝凝固过程中形成,并具有较大尺寸;细小的二次碳氮析出物能在堆焊热处理后大量弥散析出,对基体产生明显硬化作用.硬面合金中的碳氮析出沿位错和晶界弥散分布,抑制了富Cr析出相的形成并改善耐晶界腐蚀性能.

Abstract:: Hard carbide is obtained by using the developed nitrogen alloy self-protecting hard surface flux cored welding wire on low carbon steel plate. Nb and Ti are added to the hard face alloy as the most efficient carbon-nitrogen alloying elements. The morphology and composition of carbonitride precipitates in hard-sided carbides were studied by optical microscope, scanning electron microscopy and electron probe, and thermodynamic analysis was carried out, and the effects of carbon-nitrogen precipitates on tissues were discussed. The results show that the carbon and nitrogen precipitates in the hard face alloy are MX(M=alloying elements, X=C, N) composite carbonitrides distributed on grain boundaries and dislocations, and have different quantities and sizes under welded state and heat treatment conditions. Primary carbon-nitrogen precipitates are formed during the solidification process of the weld and have a large size; The fine secondary carbon and nitrogen precipitates can be dispersed and precipitated in large quantities after overlay welding heat treatment, which has obvious hardening effect on the matrix. The precipitation of carbon and nitrogen in hard-sided alloy is distributed along dislocation and grain boundary dispersion, which inhibits the formation of Cr-rich precipitated phase and improves the corrosion resistance of grain boundaries.