FV520B沉淀硬化不锈钢的MAG堆焊再制造力学特性

发布时间：2018-07-13 11:46

【摘要】：采用堆焊熔敷成形技术进行FV520B沉淀硬化不锈钢再制造实验,并通过与基材相应性能进行对比分析,研究FV520B不锈钢MAG堆焊再制造成形层力学特性。结果表明:FV520B不锈钢MAG堆焊再制造成形层具有高强度和高硬度特性,其抗拉强度达到1195MPa,超过基材的1092MPa,屈服强度和硬度平均值分别为776MPa和336HV,与基材的859MPa和353HV相近;但是,再制造成形层的静拉伸伸长率与冲击韧性相对较低,分别为8.72%和61J/cm2,与基材的19.67%和144J/cm2相比差距较大。试样断口和组织分析表明,MAG堆焊再制造成形层的快冷非平衡结晶板条马氏体+NbC,MoC,M23C6等碳化物沉淀强化相组织是其具有高强度和高硬度力学特性的根本原因。不过,缺少时效处理和Cu元素强化相作用,以及夹杂脆性相和大尺寸球形颗粒与基体间的弱界面作用会恶化材料受力时的变形能力,容易引起应力集中并开裂,是再制造成形层具有较低静拉伸伸长率和较差冲击韧性的主要原因。
[Abstract]:The remanufacturing experiment of FV520B precipitation-hardening stainless steel was carried out by using surfacing and cladding forming technology, and the mechanical properties of FV520B stainless steel MAG surfacing and remanufacturing layer were studied by comparing and analyzing the properties of FV520B stainless steel. The results show that the WFV520B stainless steel MAG surfacing layer has high strength and high hardness, and its tensile strength is 1195 MPA, which is higher than 1092 MPA of substrate. The average yield strength and hardness are 776 MPA and 336 HVrespectively, which are close to 859 MPA and 353 HV of the substrate. The static tensile elongation and impact toughness of the remade forming layer are relatively low (8.72% and 61J / cm ~ 2, respectively), which is much lower than that of the substrate (19.67%) and 144J / cm ~ (2). The fracture and microstructure analysis of the specimens show that the microstructure of rapidly cooled non-equilibrium crystalline lath martensite NbCX MoCtM23C6 and other carbides is the fundamental reason for its high strength and high hardness mechanical properties. However, the lack of aging treatment and the strengthening phase of Cu, as well as the weak interface between the inclusion brittle phase and the large spherical particle and the matrix, will worsen the deformation ability of the material under stress, which will easily lead to stress concentration and cracking. It is the main reason of low static tensile elongation and poor impact toughness.
【作者单位】：装甲兵工程学院机械产品再制造国家工程研究中心;装甲兵工程学院装备再制造技术国防科技重点实验室;
【基金】：国家自然科学基金资助项目(51405510,51375492,51575527)
【分类号】：TG457.11

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