摘要
通过热模拟试验、热轧试验,结合金相分析等研究不同Mn含量低合金钢的连续冷却相变规律,探讨Mn对低合金钢组织性能及强化机制的影响。结果表明:Mn能降低钢的相变开始温度(A_(r3))和相变结束温度(A_f),降低形成贝氏体的临界冷速,Mn的质量分数每增加0.1%,可使Ar3降低8.6℃,Af降低13.3℃;随Mn含量的升高,试验钢中的铁素体晶粒尺寸逐渐减小、珠光体含量增多、试验钢的强韧性提高、,塑性稍有降低;Mn的质量分数达到1.60%时,在4℃/s低冷速下即出现大量的贝氏体组织,塑韧性均有大幅降低。细晶强化和固溶强化是试验钢的主要强化方式,其中细晶强化效果大于固溶强化效果。Mn的质量分数为0.1%时引起的屈服强度增量约为10 MPa,其中细晶强化分量约为6 MPa,固溶强化分量约为4 MPa,引起的抗拉强度增量约为13 MPa。
The continuous cooling transformation behavior and strengthening mechanism of low alloy steel with different Mn contents were investigated by means of thermal simulation test and hot rolling test and microstructure observation.The result shows that Mn can suppress the transformation process and lower the starting temperature of transformation(Ar3)and the finishing temperature of transformation(Af),and can decrease the critical cooling rate of bainite transformation.The increase of Mn content of 0.1%(mass fraction)can reduce Ar3 by 8.6℃and Af by 13.3℃,respectively.W ith the increase of Mn content,the ferrite grain size decreases and the volume fraction of pearlite increases gradually,and the strength and toughness increase while the elongation decreases slightly.When the Mn content reaches 1.60%(mass fraction),bainite transformation occurs under a low cooling rate of 4℃/s and the ductility and toughness decrease greatly.Grain refinement strengthening and solid solution strengthening are the main strengthening modes,in which the effect of grain refinement is greater than that of solid solution.The yield strength increment caused by 0.1%of Mn content is about 10 MPa,in which the grain refinement strengthening is about 6 MPa and the solid solution strengthening is about 4 MPa.The tensile strength increment caused by 0.1%of Mn content is about 13 MPa.
作者
陆春洁
邵伟
镇凡
曲锦波
LU Chunjie;SHAO Wei;ZHEN Fan;QU Jinbo(Institute of Research of Iron and Steel (IRIS),Jiangsu Sha-steel,Zhangjiagang 215625,China)
出处
《兵器材料科学与工程》
CAS
CSCD
北大核心
2019年第2期64-69,共6页
Ordnance Material Science and Engineering
关键词
MN含量
低合金钢
CCT曲线
强化机制
细晶强化
固溶强化
Mn content
low alloy steel
CCT curve
strengthening mechanism
grain refinement strengthening
solid solution strengthening
