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本文对实验室制备的高纯净微合金钢的连续冷却转变行为进行了实验研究，并和成分相近的工业钢X60作了比较，高纯净钢的O，S，P和H杂贸总和小于0．0061％（质量分数），S，P含量各比工业钢试样低一个数量级，研究表明高纯净度降低钢在连续冷却转变时α相的非均匀形核率，导致纯净钢的贝氏体转变温度明显降低；添加硼使A3温度提高并延缓铁索体生成，有利于贝氏体和马氏体生成；在奥氏体区900℃的变形提高纯净钢的贝氏体转变温度，高纯净钢均匀化处理后在一定冷速范围内连续冷却能够获得微米级尺寸的组织和较好的强化效果，而工业钢连续冷却时仅得到较粗大的板条状贝氏体与多边形铁素体的混合组织，因此，高纯净度可以改变钢中奥氏体分解的转变动力学特别是α相的形核动力学，而且在足够高的纯净度和适当冷速条件下新相可能主要以均匀形核方式形成
In this paper, the continuous cooling transformation behavior of high purity microalloyed steel prepared in laboratory was studied and compared with X60, an industrial steel with similar composition. The total sum of O, S, P and H of high purity steel was less than zero. 0061% (mass fraction), S and P contents are each an order of magnitude lower than that of industrial steel. The results show that the high purity decreases the non-uniform nucleation rate of α phase during continuous cooling transformation, resulting in the bainite transformation of pure steel Temperature was significantly reduced; adding boron increased the temperature of A3 and delayed the formation of ferrite, which was beneficial to the formation of bainite and martensite. The deformation at 900 ℃ in austenite region increased the bainite transformation temperature of pure steel, Continuous cooling after cooling treatment within a certain range of cooling speed can achieve microstructure and better strengthening effect in the micron size range, while the continuous cooling of the industrial steel only obtains the mixed structure of coarser lath bainite and polygonal ferrite Therefore, the high purity can change the transformation kinetics of austenite decomposition in steel, especially the alpha-phase nucleation kinetics, and under the condition of high enough purity and proper cooling rate, the new phase may mainly Uniform nucleation is formed