摘要
采用Linseie L78 RITA淬火/相变热膨胀仪测定了DH36高强度船板钢的相变点,绘制了连续冷却转变曲线。通过光学显微镜和显微硬度法分析了冷却速率对相变组织演变规律及对针状铁素体形成的影响。结果表明:冷却速率0.5~3℃/s时,转变产物为多边形铁素体和珠光体;冷却速率5~10℃/s时,转变产物为大量针状铁素体和少量贝氏体,珠光体消失;冷却速率15~100℃/s时,转变产物主要由粒状贝氏体和铁素体组成,并开始形成板条马氏体,随冷速的增加其显微硬度呈增大趋势。5~7℃/s的冷却速率范围是获得针状铁素体的最佳冷速区间,在7℃/s冷速下,观察到了Al-Si-Ti-O-S-Mn系复合夹杂物所诱发的呈发散状多维形核的晶内针状铁素体。
The transformation points of DH36 high strength ship plate steel were determined by Linseie L78 RITA dilatometer. The continuous cooling transformation curves were drawn. The effects of cooling rate on the microstmcture evolution and formation of acicular ferrite were investigated by optical microscope and microhardne^s measurement. The results show that when the cooling rate is 0.5-3 ℃/s, the transformation products axe polygonal ferrite and pearlite. When the cooling rate is 5-10℃/s, the transformation product are a large number ofacicular ferrite and a small amount of bainite, and the pearlite disappears. When the cooling rate is 15-100 ℃/s, the transformation product is mainly composed of granular bainite and ferrite, and begins to form lath martensite, with the increase of the cooling rate, the hardness of the product gradually rises. The cooling rate range of 5-7 ℃/s is best cooling rate range for the formation of acicular ferrite. At 7 ℃/s cooling rate, the intragranular acicular ferrite with the nucleation of divergent multi-dimensional induced by the compound inclusions is observed.
出处
《热加工工艺》
CSCD
北大核心
2017年第24期41-44,共4页
Hot Working Technology
基金
国家自然科学基金资助项目(51574106)
河北省自然科学基金重点项目(E2016209396)
河北省自然科学基金资助项目(E2017209223)
河北省高等学校高层次人才科学研究项目(GCC2014030)
