Mechanical Characteristic of Remanufacturing of FV520B Precipitation Hardening Stainless Steel Using MAG Surfacing Deposition

• Main Authors: LIU Jian, ZHU Sheng, CAI Zhi-hai, ZHANG Ping, LIU Jun, QIN Hang, TONG Yong-gang
• Format: Article
• Language: zho
• Published: Journal of Materials Engineering 2017-10-01
• Series: Journal of Materials Engineering
• Subjects: FV520B precipitation hardening stainless steel; remanufacturing; MAG surfacing; mechanical property
• Online Access: http://jme.biam.ac.cn/CN/Y2017/V45/I10/23
• ISSN: 1001-4381; 1001-4381

Surfacing deposition forming method was adopted to carry out remanufacturing experiment of FV520B precipitation hardening stainless steel. Then the mechanical property characteristic of the remanufacturing layer was tested and studied, contrasted with the corresponding property of substrate. The results show that the remanufacturing layer, formed with MAG surfacing of FV520B precipitation hardening stainless steel has mechanical characteristic with high strength and hardness, the tensile strength reaches 1195MPa, exceeds 1092MPa of substrate, yield strength is 776MPa and average hardness is 336HV, is close to the corresponding property of substrate which is 859MPa and 353HV respectively; however, the elongation and impact toughness of the remanufacturing layer is merely 8.92% and 61J/cm² respectively, it has a large gap with the corresponding property 19.72% and 144J/cm² respectively of substrate. Fracture and microstructure analysis on specimens shows that the microstructure of remanufacturing layer is fast cooling non-equilibrium crystallized lath martensite, and carbide precipitated strengthening phase such as NbC, MoC, M₂₃C₆,etc, which is the reason that remanufacturing layer has high strength and high hardness. But as lack of aging treatment and Cu strengthening phase, and the weak interface between contaminating brittle phase or large size spherical particles and substrate will deteriorate the deformability and induce stress concentration and cracking when the material is load-carrying, and is the main reason of the remanufacturing layer having lower static tensile elongation and impact toughness.