轧制拉拔对Inconel 625线材组织结构及性能的影响

Effect of Rolling and Drawing on the Structure and Properties of Inconel 625 Wires

为明确自主研发Inconel 625焊丝的优势与不足,并为优化焊丝生产工艺提供科学依据。应用SEM、XRD、室温拉伸试验和显微硬度测试等方法,分析了Inconel 625焊丝在轧制拉拔工艺后的微观组织和力学性能。结果发现,Inconel 625合金为单一的奥氏体相;变形织构使得轧制和冷拔线坯个别衍射峰强度明显升高。不同线坯的横截面金相组织为等轴晶,热轧和冷拔线坯含形变孪晶,拉拔软态线坯存在大量退火孪晶。热轧态Inconel 625线坯经固溶处理显微硬度为219.33 HV0.5;固溶处理温度和时间控制不准确会使线坯局部出现晶粒异常长大;冷拔硬态线坯硬度值受加工硬化影响增大至522.32 HV0.5,延伸率降低至4.37%。退火处理消除了合金内应力和加工硬化,使得拉拔软态线坯的最小平均晶粒尺寸从硬态的2.66μm增长至9.5μm,延伸率达到65.13%,抗拉强度为418.92 MPa。试验结果证明,自主研发的Inconel 625焊丝的各项指标均达到国内外标准要求,说明通过精确控制加工和热处理工艺,可以有效提升焊丝的性能。

SEM,XRD,room temperature tensile test,microhardness and other methods are used to analyze the microstructure and mechanical properties of Inconel 625 wire after rolling and drawing processandfinished wires at home and abroad,and clarify the advantages and shortcomings,so as to optimize the production process of the wire.The results show that the structure of Inconel625 alloy is a single austenite phase by XRD.After rolling and cold drawing,some diffraction peak intensity of wire become significantly higher than others because of deformation texture.Cross section microstructure of the different wires is equiaxed grains,deformation twins may be found in hot rolled and cold drawn wire,and a large number of annealed twins may be also observed in the soft state of drawn wire.Microhardness is 219.33 HV0.5 for solution state of rolling Inconel 625.Local grain abnormality growth may be observed if solution treatment temperature and time is inaccurate.Microhardness increased to 522.32 HV0.5 for Cold-drawn state of Inconel 625 because of work-hardening,while elongation reduced to 4.37%.The annealing treatment eliminated the internal stresses and work hardening of the cold draw alloy,so that the minimum average grain size grows to 9.5μm from 2.66μm.Elongation of 65.13%,and tensile strength of 418.92 MPa may be gained for soft drawn wire.All the indexes of the finished wires meet the requirements of domestic and foreign standards.