690 MPa级高强抗震钢板的合金化与回火工艺  

Alloying and tempering process of 690 MPa high strength seismic steel plate

作　　者：那丽岩[1] 周明荣[1] Na Liyan;Zhou Mingrong(Zhejiang Industry Polytechnic College,Shaoxing Zhejiang 312000,China)

机构地区：[1]浙江工业职业技术学院

出　　处：《金属热处理》2019年第10期140-146,共7页Heat Treatment of Metals

摘　　要：采用光学显微镜(OM)、扫描电子显微镜(SEM)、透射电子显微镜(TEM)、拉伸试验机和冲击试验机等手段,研究了Cu、Nb、Ti合金化和回火工艺对690 MPa级高强抗震钢板显微组织与力学性能的影响。结果表明,当Cu含量为0.32%、Nb含量为0.075%、Ti含量为0.015%时,钢板具有最佳的强塑性、低屈强比和低温冲击韧性;热轧态钢板的组织为粒状贝氏体+板条贝氏体+少量铁素体+少量M/A岛,板条贝氏体束宽为2~4μm,随着回火温度的升高,板条贝氏体逐渐粗化、贝氏体束宽不断增大、板条边界逐渐模糊并最终转变为不规则的块状组织;当回火温度从300℃升高至600℃时,钢板的抗拉强度呈现逐渐降低的趋势,而屈服强度变化较小,断后伸长率呈现逐渐升高的趋势,屈强比逐渐升高,0℃和-20℃冲击吸收能量呈现逐渐降低趋势,当回火温度介于300~450℃时,试验钢能够满足690 MPa级高强抗震钢板的设计要求。Effects of Cu,Nb,Ti alloying and tempering processes on the microstructure and mechanical properties of 690 MPa high strength aseismic steel plates were studied by means of optical microscopy(OM),scanning electron microscopy(SEM),transmission electron microscopy(TEM),tensile testing machine and impact testing machine.The results show that when the content of Cu is 0.32%,Nb is0.075%,Ti is 0.015%,the steel plate has the best combination of strength and plasticity,low yield ratio and low temperature impact toughness.The microstructure of the hot rolled steel plate is granular bainite+lath bainite+a small amount of ferrite+a small amount of M/A island,and the width of lath bainite bundle is about 2-4μm,with the increase of tempering temperature,the lath bainite coarsens gradually,the width of the bainite bundle increases continuously,the boundary of the lath blurs gradually and eventually transforms into irregular massive structure.When the tempering temperature rises from 300℃to 600℃,the tensile strength of steel plates decreases gradually,while the yield strength changes slightly,the elongation increases gradually,the yield strength ratio increases gradually,and the impact absorbed energy at 0℃and-20℃decreases gradually.When the tempering temperature is between 300-450℃,the tested steel can be fully filled design requirements for 690 MPa high strength aseismic steel plate.

关 键 词：690 MPa级高强抗震钢板 成分设计 回火工艺 

分 类 号：TG142.1[一般工业技术—材料科学与工程]