摘要
低碳贝氏体钢是高强度、高韧性、多用途的新型钢种,它的出现是社会需求和现代冶金技术发展的必然结果。目前,低碳贝氏体钢已经在工程机械上得到广泛应用。然而,实际生产中得到的低碳贝氏体钢并不是由单一贝氏体组织组成,往往是多种显微组织并存,因此并不能直接体现钢的力学性能与贝氏体组织之间的对应关系。针对这一情况,以低碳Mn-B-Cr-Mo-Nb钢为研究对象,在国内某钢铁公司进行控轧控冷试验。通过对终冷温度的控制,分别得到由全部粒状贝氏体,全部板条贝氏体以及粒状贝氏体+板条贝氏体组成的3种不同类型的低碳贝氏体钢。经过对这3种不同类型的贝氏体钢进行拉伸和冲击试验后发现:在化学成分相同的条件下,粒状贝氏体钢的强度最低,韧塑性最好;板条贝氏体钢板的强度最高,韧塑性最差;由粒状贝氏体+板条贝氏体组成的钢,其强度、韧塑性居中。由此可知,终冷温度对热轧钢板的显微组织和力学性能影响很大,通过对中温转变组织的控制,就可以进一步提高低碳贝氏体钢的综合力学性能。
Low-carbon bainitic steel is a new type steel with high strength, high toughness and multiple uses, its emergency is an inevitable result of social demand and the development of modem metallurgical technology. At present, the low-carbon bainitic steel is extensively used in construction machinery. However, the low-carbon bainitic steel is usually composed of several kinds of microstructures, so the corresponding relation between the mechanical performances of the steel and bainite structure cannot be directly reflected. In view of this situation, controlled rolling and cooling experiments of low-carbon Mn-B-Cr-Mo-Nb steel are carried out in a domestic iron and steel corporation. By the control of final cooling temperature, three low-carbon bainitic steels with different microstructure are obtained. They are respectively composed of granular bainite, lath bainite, and granular bainite ＋ lath bainite. After tensile and impact tests, the results indicate that under the condition of identical chemical composition, the granular bainitic steel is the lowest in strength and is the best in toughness and plasticity, the lath bainitic steel is the highest in strength and is the weakest in toughness and plasticity, and the steel composed of granular bainite and lath hainite is medium in strength, toughness and plasticity. So it can be known that the final cooling temperature plays an important role in microstructure and mechanical performances of hot rolled plate. Accordingly, the comprehensive mechanical performances of low-carbon bainitic steel can be further improved by the control of medium-temperature transformation microstructure.
出处
《机械工程学报》
EI
CAS
CSCD
北大核心
2009年第12期284-288,共5页
Journal of Mechanical Engineering
基金
江苏省高校自然科学研究计划(08KJD460012)
江苏省高校'青蓝工程'资助项目
