17-4PH沉淀硬化不锈钢力学性能稳定性研究

Research on Mechanical Properties Stability of 17-4PH Precipitated Hardened Stainless Steel

针对生产中某17-4PH钢产品力学性能不稳定,研究了原材料、锻造工艺及热处理工艺对产品力学性能的影响。结果表明：力学性能不稳定的主要原因是由于产品技术要求中强度与硬度匹配区域窄,对应强度指标要求的硬度指标偏低,原材料化学成分的波动引起力学性能的变化。通过提出产品锻造选用同批次坯料,以及增加固溶保温时间、改真空炉时效为井式炉时效,实现时效温度的精密控制,优化时效温度控制点589℃,提高了产品性能合格率。同时,优化匹配出17-4PH钢强度与硬度的性能指标为抗拉强度σb≥1000 MPa,硬度32-37 HRC,为新产品的设计提供技术支撑。

In view of the instability of mechanical properties of a certain 17-4 PH steel product in production, the effects of raw material, forging process and heat treatment process on the mechanical properties of the product were studied. The results show that, the main reason of the instability of mechanical properties is that the matching region of strength and hardness is narrow, the hardness index corresponding to strength index is low, and the fluctuation of chemical composition of raw materials causes the change of mechanical properties. By using same batch blank for product forging, increasing the time of solid solution and heat preservation, changing the aging of vacuum furnace into well furnace aging, the aging temperature is precisely controlled, and the aging temperature control point is optimized at 589 ℃, which improves the qualified rate of product performance. At the same time, the tensile strength σb≥1000 MPa and hardness of 27-32 HRC are optimized to match the strength and hardness of 17-4 PH steel, which provides technical support for the design of new products.