西南交通大学学报2025，Vol.60Issue(2)：411-417,7.DOI:10.3969/j.issn.0258-2724.20220641
两种合金密封环与浸渍石墨配副的损伤失效
Damage Failure of Two Alloy Seal Rings Paired with Impregnated Graphite
摘要
Abstract
Cr alloy seal ring and YG-6 cemented carbide seal ring were used to pair with impregnated graphite seal ring in a petrochemical pump at 300-400℃,respectively.It was found that the Cr alloy seal ring maintained good sealing performance for a long-term service,while gas leakage occurred to the cemented carbide seal ring after a short time of service.To explore the reasons for the difference in service performance of two kinds of alloy seal rings,the surface morphologies,chemical compositions,and mechanical properties of the failed seal rings were characterized,and their failure mechanisms were analyzed.The results show that the Cr alloy seal ring is made from martensitic Cr-containing steel without surface strengthening treatment,and the surface hardness and elastic modulus are(629.8±14.2)HV30 and(244.7±17.4)GPa,respectively.On its contact area with impregnated graphite,an annular wear scar characterized by a slight ploughing effect is observed,and the surface roughness of the wear significantly decreases.The surface hardness and elastic modulus of the cemented carbide seal ring are(1475.3±60.1)HV30 and(815.3±57.2)GPa,respectively.There exists high residual stress and material embrittlement induced by oxidative corrosion in the seal ring surface.No obvious wear occurs on the contact area with impregnated graphite,but blocky defects caused by oxidation cracking appear.Due to low stiffness and high surface roughness,the Cr alloy seal ring suffers from abrasive wear on its surface with impregnated graphite,but the wear surface has grinding and polishing behaviors,maintaining its good sealing performance when paired with impregnated graphite.For the YG-6 cemented carbide seal ring,defects by cracking occur in the contact area with impregnated graphite under the action of the high surface residual stress and the material oxidation and embrittlement induced by high temperatures,resulting in sealing failure.关键词
密封环/Cr合金/硬质合金/失效分析/磨粒磨损/氧化脆化Key words
seal rings/Cr alloy/cemented carbide/failure analysis/abrasive wear/oxidation embrittlement引用本文复制引用
郑靖,何佳欣,雷磊,杨丹,黄元宝,张尔卿,张车宁..两种合金密封环与浸渍石墨配副的损伤失效[J].西南交通大学学报,2025,60(2):411-417,7.基金项目
国家重点研发计划(2018YFB2000800) （2018YFB2000800）
