固溶处理中冷却方式对Inconel 625组织与性能的影响

Effect of Cooling Methods on Microstructure and Properties of Inconel 625 in Solution Treatment

为提高625合金的综合性能,通过改变固溶处理的方式,采用硬度计、拉伸试验机、电化学工作站、光学显微镜、扫描电子显微镜等设备对Inconel 625合金进行研究,探讨了5种不同热处理工艺对合金的微观组织演变规律及力学性能、腐蚀性能的影响。结果表明:原始状态的Inconel 625合金组织主要为奥氏体组织,合金硬度较高,但耐蚀性能较差。经过1090℃固溶处理、水冷后,晶界处保留了热处理过程中析出的碳化铌,提高了合金的腐蚀性能;经过空冷或炉冷,合金内重新析出碳化铬,导致合金腐蚀性能下降;特殊工艺处理可以有效提高合金的抗腐蚀性能,且在不降低强度的前提下提高材料的塑性。研究成果可为生产中优化Inconel 625合金热处理工艺进而提升材料综合性能提供有效依据。

In order to improve the comprehensive properties of Inconel 625 alloy,the alloy was studied using hardness tester,tensile machine,electrochemical workstation,optical microscope and scanning electron microscope based on a change of the solution treatment method,and the effects of five different heat treatment processes on the microstructure evolution law,mechanical properties and corrosion properties of the alloy were discussed.Results showed that the as-cast Inconel 625 alloy was mainly composed of austenite,and the alloy had high hardness but poor corrosion resistance.After a solution treatment at 1090℃and a subsequent water cooling treatment,the precipitated niobium carbide resulting from the heat treatment was retained at the grain boundary,which improved the corrosion resistance of the alloy.Air cooling or furnace cooling caused a reprecipitation of chromium carbide,resulting in a decline in the corrosion performance of the alloy.Special process treatment could effectively improve the corrosion resistance of the alloy and improve the plasticity of the material without reducing the strength.This research achievements could optimize the heat treatment process of Inconel 625 alloy in production and provide effective basis for the improvement of the comprehensive properties of the material.