摘要
采用连续退火模拟机CCT-AY-Ⅱ对中锰Q＆P钢（0.2C-5Mn-1.5Si中锰钢,锰含量4.92%）进行热处理实验,利用SEM、EBSD、拉伸试验以及X射线衍射法研究了不同退火温度对中锰Q＆P钢的组织和力学性能、残留奥氏体含量的影响。结果表明,随退火温度的升高,抗拉强度逐渐升高,屈服强度逐渐降低,伸长率和强塑积先升高后降低,在660℃奥氏体化Q＆P处理后力学性能最佳,抗拉强度为1040 MPa,断后伸长率为33.7%,强塑积达35.9 GPa·%;残留奥氏体体积分数随着退火温度的升高逐渐增多,最高达25%;试验钢对两相区奥氏体化温度非常敏感,稍高或稍低的退火温度都会导致强塑积的急剧下降,而在650-670℃之间退火时强塑积可达30.0 GPa·%以上。
Heat treatment process of a medium-manganese Q＆P （quenching and portioning） steel （0. 2C-5Mn-1.5Si） was carried out using thermal simulator CCT-AY- Ⅱ. Effects of annealing temperature on microstructure, mechanical properties, retained austenite content of the tested steel after heat treatment were investigated by means of scan electron microscope （SEM） , electron baekseattered diffraction （EBSD）, tensile test and X-ray diffraction （XRD）. The results show that, with annealing temperature increasing, the tensile strength gradually increases and the yield strength decreases, the product of strength and elongation increases at first and then decreases, the maximum values of elongation （33.7%） and product of strength and elongation （35.9 GPa·% ） are obtained for the steel annealed at 660 ℃. The volume fraction of retained austenite gradually increases up to 25% with annealing temperature increasing. The tested steel is very sensitive to the austenitizing temperature, therefore slightly higher or lower annealing temperature ean lead to sharp decrease in strength and elongation. The product of strength and elongation can approach up to 30. 0 GPa.% or more when annealing temperature is between 650 ℃ and 670 ℃.
出处
《材料热处理学报》
EI
CAS
CSCD
北大核心
2015年第7期42-47,共6页
Transactions of Materials and Heat Treatment
基金
高等学校博士学科点专项科研基金(20110006110007)
中央高校基本科研业务费资助项目(FRF-TP-11-005B)
关键词
中锰钢
Q&P工艺
两相区退火
亚稳奥氏体
应力应变
medium-manganese steel
quenching and partitioning process
intercritieal annealing
metastable austenite
stress-strain
