摘要
基于货油舱用耐蚀钢的服役环境设计并冶炼了一种新型耐蚀钢,根据试验钢变形奥氏体连续转变曲线,采用控制轧制和控制冷却的技术将锻后110 mm坯料减薄至16 mm。热轧板材的年平均腐蚀速率分布在0.235~0.273 mm/a,小于船级社要求的1 mm/a。利用扫描电镜、透射电镜、拉伸试验机和冲击试验机进行了耐蚀钢的显微结构分析及力学性能研究,探究了控制冷却工艺对耐蚀钢组织性能的影响规律。结果表明:在终冷温度669℃、冷却速度8.9℃/s的条件下,耐蚀钢显微组织主要为铁素体、贝氏体和退化珠光体。降低终冷温度或提高冷却速率有利于抑制珠光体转变,促进针状铁素体和贝氏体相变进程,增加小角度晶界数量,提高耐蚀钢的组织均匀性和力学性能。当终冷温度降低至597℃,冷却速度增大到13.1℃/s,耐蚀钢组织为针状铁素体、粒状贝氏体和板条贝氏体混合结构,不均匀分布且粗大尺寸的板条结构弱化了材料的抗冲击性能。
A new type of corrosion resistant steel was designed and smelted based on the service environment of cargo oil tank.According to the continuous cooling transformation curve of deformed austenite,the forged billet was thinned from 110 mm to 16 mm using controlled rolling and controlled cooling technology.The average annual corrosion rate of hot rolled plate is 0.235~0.273 mm/a,less than 1 mm/a required by classification society.The microstructure and mechanical properties of corrosion resistant steel were analyzed by scanning electron microscopy(SEM),transmission electron microscopy(TEM),tensile testing machine and impact testing machine,the influence of cooling process on the performance of corrosion resistant steel was studied.The results showed that the microstructure of corrosion resistant steel was mainly ferrite,bainite and degenerate pearlite atthe final cooling temperature of 669℃and the cooling speed of 8.9℃/s.Reducing the final cooling temperature or increasing the cooling speed is beneficial to inhibit the pearlite transformation,promote transition process of acicular ferrite and bainite,increasing the number of small angle grain boundary,and improve mechanical properties and homogeneity of corrosion resistant steel.When the final cooling temperature drops to 597℃,the cooling speed increases to 13.1℃/s,the microstructure is a mixture of acicular ferrite,granular bainite and lath-like bainite,the uneven distribution and large size of the lath bainite weaken the impact resistance of the material.
作者
于驰
王宏岩
高秀华
王宏伟
YU Chi;WANG Hongyan;GAO Xiuhua;WANG Hongwei(The State Key Laboratory of Rolling and Automation(Northeastern University),Shenyang 110819,China;Northeastern University at Qinhuangdao,Qinhuangdao 066004,China)
出处
《材料科学与工艺》
EI
CAS
CSCD
北大核心
2020年第4期31-40,共10页
Materials Science and Technology
基金
中国博士后科学基金资助项目(2018M631761)
中央高校基本科研业务专项资金资助项目(N182303030)。
关键词
耐蚀钢
冷却工艺
腐蚀速率
显微组织
力学性能
corrosion resistant steel
cooling process
corrosion rate
microstructure
mechanical properties
