Fedoriková Alica, Petroušek Patrik, Kvačkaj Tibor, Kočiško Róbert, Zemko Michal
Department of Material Analysis, Research Centre Řež Ltd., Hlavní 130, 250 68 Husinec, Czech Republic.
Department of Plastic Deformation and Simulation Processes, Institute of Materials and Quality Engineering, Faculty of Materials, Metallurgy and Recycling, Technical University of Kosice, Park Komenského 11, 040 01 Kosice, Slovakia.
Materials (Basel). 2023 Sep 29;16(19):6473. doi: 10.3390/ma16196473.
The article deals with increasing the mechanical properties of stainless steel 316 Ln-IG, which is intended for work in cryogenic temperatures (liquid nitrogen and liquid helium), such as conductor conduits for the ITER magnet system. The strength and plastic properties were increased by a combination of cold and cryo-rolling and heat treatment. The mechanical properties of rolled material were investigated at 293 K, 77 K, and 4.2 K. The work-hardening rate of the steel increased continuously with a lowering of the temperature. The maximum yield strength and ultimate tensile strength were achieved by the cryo-rolling process with a total thickness deformation of 50%. The material properties tested at ambient temperature were 0.2YS = 1050 MPa, UTS = 1200 MPa, and at 4.2 K, the values were 0.2YS = 1804 MPa and UTS = 2081 MPa. Two types of long-term heat treatment were applied after experimental rolling (823 K and 1093 K for 10 h). The highest precipitation hardening of steel was achieved at a temperature of 823 K after 50% deformation. The resulting grain size decreased from the initial 216 μm (before the rolling process) to 70 μm after ambient rolling and 72 μm after cryo-rolling.
本文探讨了提高316 Ln-IG不锈钢机械性能的方法，该不锈钢用于低温环境（液氮和液氦）工作，如ITER磁体系统的导体管道。通过冷加工、低温轧制和热处理相结合的方式提高了强度和塑性性能。对轧制材料在293 K、77 K和4.2 K温度下的机械性能进行了研究。随着温度降低，钢的加工硬化速率持续增加。通过总厚度变形为50%的低温轧制工艺实现了最大屈服强度和极限抗拉强度。在室温下测试的材料性能为0.2YS = 1050 MPa，UTS = 1200 MPa，在4.2 K时，数值分别为0.2YS = 1804 MPa和UTS = 2081 MPa。在实验轧制后进行了两种类型的长期热处理（823 K和1093 K，保温10小时）。在50%变形后，823 K温度下实现了钢的最高沉淀硬化。最终晶粒尺寸从轧制前的初始216μm减小到室温轧制后的70μm和低温轧制后的72μm。
