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为了研究Al和P合金元素在TRIP钢固态相变过程中的作用,研究了4种不同合金成分C-Mn-Al-P TRIP钢的CCT图。结果表明,Al元素强烈的缩小奥氏体相区,提高Ac3与Ms。Al元素促使CCT图左移和上移。P元素能够阻碍碳化物的生成,当钢中P含量达到0.14%,能显著的将CCT图中的珠光体区与贝氏体区右移。P元素对铁素体相变和马氏体相变没有显著影响。利用类平衡下切变长大模型估算了4种TRIP钢的Bs点(A6钢为567℃,P1钢为556℃,P2钢为514℃,P3钢为548℃),与实际测量值吻合较好。研究表明在相同条件下,Al元素降低ΔμFγ→e,cαh,即增加相变驱动力,同时还降低ΔGmsh,eFaer,即降低切变阻力,提高Bs点。P元素增加ΔGmsh,eFaer,即增加切变阻力,降低Bs点。
In order to study the role of Al and P alloying elements in the solid state transformation of TRIP steels, the CCTs of four different alloy compositions of C-Mn-Al-P TRIP steels were studied. The results show that the Al element strongly reduces the austenite phase and enhances Ac3 and Ms. The Al element causes the CCT chart to move left and up. P element can hinder the formation of carbides. When the P content in steel reaches 0.14%, the pearlite zone and bainite zone in the CCT diagram can be significantly shifted to the right. P element has no significant effect on ferrite transformation and martensitic transformation. The Bs-points (567 ℃ for A6 steel, 556 ℃ for P1 steel, 514 ℃ for P2 steel and 548 ℃ for P3 steel) were estimated by using the quasi-shear-and-grow-type equilibrium model, which is in good agreement with the actual measured values . The results show that under the same conditions, Al decreases ΔμFγ → e, cαh, that is, increases the driving force of phase transformation, and decreases ΔGmsh, eFaer, which decreases the shear resistance and increases the Bs point. P element increase ΔGmsh, eFaer, that is, increase the shear resistance, reduce the Bs point.