钒微合金化低碳贝氏体钢的连续冷却相变特性

 采用热膨胀法测定6种不同成分低碳贝氏体钢的连续冷却转变(CCT)曲线。CCT曲线表明，加入微量硼能使含钒低碳贝氏体钢在大于03℃/s的冷速下获得贝氏体组织，而V-N微合金化的低碳贝氏体获得全贝氏体的临界冷速要高于V-B钢，且贝氏体转变的开始温度也要较V-B钢高20℃左右。在含钒、氮低碳贝氏体钢中加入钼、铬将会促进钢的贝氏体相变，但钼的作用要优于铬；钼、铬的加入可使含钒、氮低碳贝氏体钢的贝氏体转变温度降低至少30℃，且贝氏体组织得到了细化，钢的维氏硬度也提高了HV10~30。

Phase Transformation Characteristics of Vanadium Microalloying Low Carbon Bainitic Steel in Continuous Cooling Process

The continuous cooling transformation (CCT) curves of experimental steels were tested with heat dilatometer. The results show that the low carbon steel containing V and B can obtain fully bainitic microstructures more than 03℃/s of cooling rate. Compared to V-B steel, low carbon steels microalloying with V-N have higher critical cooling rate to achieve fully bainite, also bainite start temperature is about 20℃ higher than V-B steel. The element of Mo and Cr additions to V-N microalloyed low carbon steels can promote bainite transformation and Mo is more effective than Cr. Adding Mo and Cr into V-N microalloyed low carbon bainitic steels can lower bainite transformation temperature at least 30℃ and refine bainitic microstructures, thus increase the Vickers hardenss HV10-30.