摘要
通过单道次、双道次压缩试验,研究了低Ni型LNG钢的高温奥氏体动态再结晶及静态再结晶行为,并采用两阶段控制轧制及超快速冷却技术进行不同轧制工艺下的热轧试验,通过热模拟及热轧试验研究了低Ni型LNG钢的热变形行为及力学性能。结果表明,在高温(1000~1050℃)、低应变速率(0.1~0.5 s^(-1))下奥氏体容易发生动态再结晶,确定了发生再结晶的临界条件,并建立了动态再结晶动力学模型。试验钢在较高温度(800~1050℃)、较长道次间隔时间(60 s)下静态软化现象明显,容易发生静态再结晶。依据热模拟试验结果制定热轧试验工艺,通过控制精轧开轧温度和终轧温度调控高温奥氏体再结晶行为,从而细化晶粒,改善低Ni钢的冲击性能。精轧开轧温度920℃、终轧温度770℃时,低Ni钢的低温冲击吸收能量为180.1 J,屈服强度为595.1 MPa,抗拉强度为717.8 MPa。
High-temperature austenite dynamic recrystallization and static recrystallization behaviors of a low Ni type LNG steel were studied through single-pass and double-pass compression tests,and through hot rolling tests under different rolling processes by two-stage controlled rolling and ultra-rapid cooling technologies,and then hot deformation behavior and mechanical properties of the low Ni type LNG steel were studied through thermal simulation and hot rolling test.The results show that dynamic recrystallization of austenite is easy to occur at high temperature(1000-1050℃)and low strain rate(0.1-0.5 s^(-1)),the critical conditions for the occurrence of recrystallization are determined,and a dynamic recrystallization kinetic model is established.The static softening phenomenon of the tested steel is obvious and static recrystallization is easy to occur at higher temperature(800-1050℃)and longer pass interval(60 s).According to the results of the thermal simulation test,the hot rolling test process is formulated,and the recrystallization behavior of high temperature austenite is controlled by controlling the finishing rolling temperature and the finishing rolling temperature,so as to refine the grains and improve the impact properties of the low Ni steel.When the finishing rolling temperature is 920℃and the finishing rolling temperature is 770℃,the impact absorbed energy at low temperature of the low Ni steel is 180.1 J,the gield strength is 595.1 MPa,and the tensile strength is 717.8 MPa.
作者
党玉珍
蔡晓辉
陈其源
刘振宇
Dang Yuzhen;Cai Xiaohui;Chen Qiyuan;Liu Zhenyu(State Key Laboratory of Rolling and Automation,School of Materials Science and Engineering,Northeastern University,Shenyang Liaoning 110819,China)
出处
《金属热处理》
CAS
CSCD
北大核心
2022年第6期148-154,共7页
Heat Treatment of Metals
基金
国家重点研发计划(2017YFB0305000)。
关键词
低Ni型LNG钢
再结晶
控制轧制
力学性能
low Ni type LNG steel
recrystallization
controlled rolling
mechanical properties
