Panov Dmitry, Pertsev Alexey, Smirnov Alexander, Khotinov Vladislav, Simonov Yuri
Department of metal science, thermal and laser processing of metals, Perm National Research Polytechnic University, 29 Komsomolsky prospekt, 614990 Perm, Russia.
Department chief Metallurgist, Perm scientific-research technological Institute, 41 Geroev Khasana Street, 614990 Perm, Russia.
Materials (Basel). 2019 Jun 26;12(13):2058. doi: 10.3390/ma12132058.
The article presents the influence of structure formation on the properties of 321 metastable austenitic stainless steel in the process of cold radial forging (CRF). The steel under study after austenitization was subjected to CRF at room temperature with degrees of true strain (e) 0.26, 0.56, 1.00, 1.71 and 2.14. It has been shown that structure formation of the studied steel during CRF consists of three stages: formation of the lamellar structure of austenite, formation of the trapezoidal structure, and formation of the equiaxial grain structure. The kinetics of the strain-induced α'-martensitic transformation is related to the stages of structure evolution. Hardness, ultimate tensile strength and yield strength uniformly increase in all stages of structure formation with a significant decrease of elongation to fracture during the first stage of structure formation while the value of elongation to fracture remains constant in the subsequent stages of deformation. Impact strength of fatigue cracked specimens (KCT) decreases sharply at the first stage of structure formation and smoothly increases at the second and third stages. However, the impact strength of V-notch specimens (KCV) continuously decreases when deformation degree increases in the overall investigated deformation range.
本文介绍了在冷径向锻造（CRF）过程中，组织形成对321亚稳奥氏体不锈钢性能的影响。所研究的钢在奥氏体化后，于室温下进行冷径向锻造，真应变（e）分别为0.26、0.56、1.00、1.71和2.14。结果表明，所研究钢在冷径向锻造过程中的组织形成包括三个阶段：奥氏体片层组织的形成、梯形组织的形成和等轴晶粒组织的形成。应变诱导α'马氏体相变的动力学与组织演变阶段有关。在组织形成的所有阶段，硬度、抗拉强度和屈服强度均呈均匀增加，而在组织形成的第一阶段，断裂伸长率显著降低，在随后的变形阶段，断裂伸长率保持恒定。疲劳裂纹试样（KCT）的冲击强度在组织形成的第一阶段急剧下降，在第二和第三阶段平稳增加。然而，在整个研究的变形范围内，随着变形程度的增加，V型缺口试样（KCV）的冲击强度持续下降。
