Abstract: As the main material used in ships and their equipment, steel is prone to corrosion due to working in high-salinity seawater environment for a long time, which affect its service life. In China, the annual loss of the hull steel caused by seawater corrosion even exceeds 50% of the total loss, which imposes significant hindrance on the development of the marine industry. The effects of the ultrasonic-aided quenching (USQ) heat treatment process on the microstructure and corrosion resistance of the sample is studied by the metallographic analysis, grain size statistics and electrochemical corrosion test of the 35CrMo steel used in rudder stock. The results show that in the microstructure of the USQ sample, the residual austenite disappears, the size and the uniformity of the grains are improved together with the significantly enhanced corrosion resistance.

Key words: ultrasonic-aided quenching, microstructure, grain size, corrosion

摘要： 钢材作为船舶及其设备的主要构件材料,因长期工作在高盐度海水环境中,极易发生腐蚀现象,进而影响其服役寿命,我国每年因海水腐蚀所造成的损失甚至超过总损失量的50%,已严重阻碍了海洋产业的发展进程。该文以舵杆用35CrMo钢为例,通过金相组织分析、晶粒尺寸统计和电化学腐蚀试验,研究超声波辅助淬火热处理工艺对试样显微组织和耐腐蚀性能的影响。结果表明：超声波辅助淬火试样的微观组织中,残余奥氏体消失,晶粒的尺寸和均匀性得到改善,耐腐蚀性能得到显著提高。

关键词: 超声波辅助淬火, 微观组织, 晶粒尺寸, 腐蚀性能