CAJ | 학술논문

快速凝固技术是改善高铬钢表面性能的有效手段,其中激光熔凝处理最为简单经济.过去,对采用激光熔凝处理来提高材料耐蚀性的报道不多,为此,采用5 kW横流CO2激光器对高铬钢进行熔凝强化处理,借助电化学测试、扫描电镜等方法研究了高铬钢激光熔凝处理后的显微组织及耐蚀性能.结果表明:高铬钢的表面腐蚀始于碳化物与基体交界处,导致基体腐蚀严重,大量碳化物暴露于表面;激光熔凝处理明显改善了高铬钢的组织形态,使其晶粒细化,碳化物完全溶解,碳及合金元素固溶于奥氏体枝晶中,耐蚀性明显提高,腐蚀表面均匀平整.
쾌속응고기술시개선고락강표면성능적유효수단,기중격광용응처리최위간단경제.과거,대채용격광용응처리래제고재료내식성적보도불다,위차,채용5 kW횡류CO2격광기대고락강진행용응강화처리,차조전화학측시、소묘전경등방법연구료고락강격광용응처리후적현미조직급내식성능.결과표명:고락강적표면부식시우탄화물여기체교계처,도치기체부식엄중,대량탄화물폭로우표면;격광용응처리명현개선료고락강적조직형태,사기정립세화,탄화물완전용해,탄급합금원소고용우오씨체지정중,내식성명현제고,부식표면균균평정.
A 5 kW continuous CO2 laser sys-tem was performed for laser surface melting of high chrome steel.The microstructure and corrosion resistance of the laser surface melting modified layer were analyzed by using it scanning electron microscope and an electrochemical test rig. Results show that the high chrome steel experienced initial corrosion attack at the boundary of the carbides and matrix, leading to severe corrosion of the matrix and exposure of a large amount of carbides on the corroded surface. Laser surface melting obviously modified the structure of the as- received steel, leading to the refined grains,complete dissolution of reticular carbides, as well as solid solu-tion of C and alloying elements in austenite dendrites. The corro-sion resistance of steel increased.