材料期刊网

采用Gleeble-1500热模拟试验机,建立了10Ni5CrMo钢的连续冷却转变曲线。分析了10Ni5CrMo钢在不同冷却速度下的组织转变规律。结果表明：当冷却速度小于0.2℃/s时,钢中得到粒状贝氏体组织;当冷却速度为0.5℃/s时,组织为粒状贝氏体和下贝氏体;当冷却速度在1～2℃/s时,组织为板条状的马氏体和贝氏体的混合组织;当冷速进一步增大,达到5℃/s时,钢中得到了单一的马氏体组织。为了研究冷却速度对强度和低温韧性的影响,在实验室采用不同冷却方式模拟不同的冷却速度并进行冲击和拉伸试验,试验结果表明：不同冷却方式下钢的强度相差不大,低温冲击韧性有较大提高。对不同冷却方式下的精细结构进行深入分析,马贝混合细化了板条块及板条束。研究认为适当比例的马贝混合组织能提高10Ni5CrMo钢的低温韧性。

The simulated continuous cooling transformation curve of 10Ni5CrMo steel was made by Gleeble-1500.By the metallographic analysis,the rules of phase transformation change of 10Ni5CrMo at different cooling rate were investigated.The results show that when cooling rate is lower than 0.2 ℃/s,the microstructure is granular bainite.When cooling rate is up to 0.5 ℃/s,the microstructure is granular bainite a lower bainite.When cooling rates is between 1 ℃/s and 2 ℃/s,the main microstructure of the 10Ni5CrMo steel is the combination of the bainite and martensite.When cooling rates increase further,the microstructure is simple martensite.In order to study the cooling rates to the affect of the strength and low temperature toughness,different cooling process simulation experiment was carried out in the lab and tested the stretching and impact.The results show that the strength of the different cooling ways is similar and low-temperature impact toughness is improved.Fine structure of different cooling way was in-depth analysised.The test results indicate that block and packet size can be refined.Low-temperature impact toughness of 10Ni5CrMo steel can be increased by controlling proper proportion of bainite and martensite.