Study of the microstructure and mechanical performance of C-X stainless steel processed by selective laser melting (SLM)
Study of the microstructure and mechanical performance of C-X stainless steel processed by selective laser melting (SLM)
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DOI：
10.1016/j.msea.2020.139227
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发表时间：
2020-04
期刊：
影响因子：
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通讯作者：
Xingchen Yan;Chaoyue Chen;Cheng-Chia Chang;Dongdong Dong;R. Zhao;R. Jenkins;Jiang Wang;Z. Ren-
中科院分区：
文献类型：
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作者：
Xingchen Yan;Chaoyue Chen;Cheng-Chia Chang;Dongdong Dong;R. Zhao;R. Jenkins;Jiang Wang;Z. Ren-
采用选择性激光熔化技术制备了一种新型沉淀硬化不锈钢（PHSS）--C-X不锈钢。在SLM制造之后，施加一系列热处理以改善竣工样品的机械性能。采用扫描电镜（SEM）、X射线衍射（XRD）和透射电镜（TEM）对SLM C-X不锈钢在铸态和热处理态下的组织、析出相分布和演变规律以及力学性能进行了系统研究。XRD谱表明，固溶处理导致形成完整的马氏体相，并且在时效处理后形成逆转变奥氏体（“奥氏体”）相。TEM分析表明，大量的位错和纳米沉淀物分散在马氏体基体内的建成和老化样品。通过高分辨透射电镜（HRTEM）、选区电子衍射（SAED）和X射线能谱（EDS）等分析手段，对铸态样品和固溶时效样品的NiAl析出相进行了表征，结果表明，NiAl析出相为棒状，尺寸范围为3-25 nm，固溶时效样品为7-30 nm。此外，SLM C-X不锈钢零件的显微硬度也有显著提高，从350 HV 0. 2提高到固溶时效态的510 HV 0. 2。SLM C-X不锈钢部件的极限拉伸强度（UTS）也从完工状态的1043 MPa增加到固溶时效热处理后的1601 MPa。
In this study, a new precipitation hardening stainless steel (PHSS), C-X stainless steel, was manufactured using selective laser melting (SLM) technology. Following SLM fabrication, a series of heat treatments were applied to improve the mechanical properties of the as-built samples. The microstructure precipitates distribution and evolution, and mechanical properties of SLM C-X stainless steels in the as-built and heat-treated conditions were systematically studied using scanning electron microscope (SEM), X-ray diffraction (XRD), and transmission electron microscope (TEM). The XRD spectrum revealed that solution treatment resulted in the formation of a complete martensite phase, and a reverted austenite (γ’) phase formed after aging treatment. The TEM analysis indicated that numerous dislocations and nanoprecipitates were dispersed within the martensite matrix for both the as-built and aged samples. The rod-like NiAl precipitates with a size range of 3–25 nm for the as-built samples and 7–30 nm for the solution-aged samples were determined through high-resolution TEM (HRTEM), selected area electron diffraction (SAED), and energy-dispersive X-ray spectroscopy (EDS). Furthermore, the microhardness of the SLM C-X stainless steel parts was found to significantly improve from 350 HV0.2in the as-built state to 510 HV0.2in the solution-aged state. The ultimate tensile strength (UTS) of the SLM C-X stainless steel parts also increased from 1043 MPa in the as-built state to 1601 MPa after solution-aging heat treatment.