Deformation-induced ferrite transformation （DIFT） has been proved to be an effective approach to refine ferrite grains. This paper shows that the ferrite grains can further be refined through combination of DIFT and...Deformation-induced ferrite transformation （DIFT） has been proved to be an effective approach to refine ferrite grains. This paper shows that the ferrite grains can further be refined through combination of DIFT and V or V-N microalloying. Vanadium dissolved in γ matrix restrains DIFT. During deformation, vanadium carbonitrides rapidly precipitate due to strain-induced precipitation, which causes decrease in vanadium dissolved in matrix and indirectly accelerates DIFT. Under heavy deformation, deformation induced ferrite （DIF） grains in V microalloyed steel were finer than those in V free steel. The more V added to steel, the finer DIF grains obtained. Moreover, the addition of N to V microalloyed steels can remarkably accelerate precipitation of V, and then promote DIFT. However, DIF grains in V-N microalloyed steel easily coarsen.展开更多
Processing maps for a medium carbon V-N microalloyed steel(designated as VN steel) and a medium carbon V-N bared steel(designated as Non-VN steel) were developed to study the hot deformation behavior and the influence...Processing maps for a medium carbon V-N microalloyed steel(designated as VN steel) and a medium carbon V-N bared steel(designated as Non-VN steel) were developed to study the hot deformation behavior and the influence of vanadium and nitrogen, in the temperature range of 750-1 100 ℃ and strain rate range of 0.005-30 s-1. Experimental results show that the processing map for the VN steel exhibits two dynamic recrystallization and three instability domains, while that for the Non-VN steel has one dynamic recrystallization and three instability domains. The instability domains of VN steel are larger than those of the Non-VN steel, and the VN steel is easier to be unstable when being hot deformed at high temperature and high stain rate. The addition and precipitation of vanadium and nitrogen can hinder the dynamic recrystallization. Compared with the Non-VN steel, the VN steel has higher dynamic recrystallization critical strain and the corresponding stress.展开更多
对经1 055 ℃正火和765 ℃回火优化工艺生产的9Cr 1Mo V Nb N厚壁无缝钢管,进行室温和 566 ℃的静力强塑性的检测和评估,就取样位置和取样方向对强塑性的影响进行了 t统计检验评估及强塑性的标准偏差评估。结果表明,按优化工艺生产的9Cr...对经1 055 ℃正火和765 ℃回火优化工艺生产的9Cr 1Mo V Nb N厚壁无缝钢管,进行室温和 566 ℃的静力强塑性的检测和评估,就取样位置和取样方向对强塑性的影响进行了 t统计检验评估及强塑性的标准偏差评估。结果表明,按优化工艺生产的9Cr 1Mo V Nb N厚壁无缝钢管显著优于1 050 ℃正火和790 ℃回火原工艺生产的厚壁无缝钢管,强塑性指标及其标准偏差已达到进口P91厚壁无缝钢管的水平,表明我国9Cr 1Mo V Nb N厚壁无缝钢管的制造技术已日趋成熟。展开更多
对9Cr 1Mo V Nb N钢厚壁无缝管研制品与进口住友P91钢管在供货状态下进行了比较研究,测试了两者的静力拉伸强塑性,分析了其间存在的差异.结果表明,研制品的强塑性与进口管相差尚少,但钢中杂质元素的控制与住友钢管有一定差距,质量均... 对9Cr 1Mo V Nb N钢厚壁无缝管研制品与进口住友P91钢管在供货状态下进行了比较研究,测试了两者的静力拉伸强塑性,分析了其间存在的差异.结果表明,研制品的强塑性与进口管相差尚少,但钢中杂质元素的控制与住友钢管有一定差距,质量均匀性有待提高.展开更多
文摘Deformation-induced ferrite transformation （DIFT） has been proved to be an effective approach to refine ferrite grains. This paper shows that the ferrite grains can further be refined through combination of DIFT and V or V-N microalloying. Vanadium dissolved in γ matrix restrains DIFT. During deformation, vanadium carbonitrides rapidly precipitate due to strain-induced precipitation, which causes decrease in vanadium dissolved in matrix and indirectly accelerates DIFT. Under heavy deformation, deformation induced ferrite （DIF） grains in V microalloyed steel were finer than those in V free steel. The more V added to steel, the finer DIF grains obtained. Moreover, the addition of N to V microalloyed steels can remarkably accelerate precipitation of V, and then promote DIFT. However, DIF grains in V-N microalloyed steel easily coarsen.
基金Project supported by Vanadium International Technical Committee(VANITEC)
文摘Processing maps for a medium carbon V-N microalloyed steel(designated as VN steel) and a medium carbon V-N bared steel(designated as Non-VN steel) were developed to study the hot deformation behavior and the influence of vanadium and nitrogen, in the temperature range of 750-1 100 ℃ and strain rate range of 0.005-30 s-1. Experimental results show that the processing map for the VN steel exhibits two dynamic recrystallization and three instability domains, while that for the Non-VN steel has one dynamic recrystallization and three instability domains. The instability domains of VN steel are larger than those of the Non-VN steel, and the VN steel is easier to be unstable when being hot deformed at high temperature and high stain rate. The addition and precipitation of vanadium and nitrogen can hinder the dynamic recrystallization. Compared with the Non-VN steel, the VN steel has higher dynamic recrystallization critical strain and the corresponding stress.
文摘对经1 055 ℃正火和765 ℃回火优化工艺生产的9Cr 1Mo V Nb N厚壁无缝钢管,进行室温和 566 ℃的静力强塑性的检测和评估,就取样位置和取样方向对强塑性的影响进行了 t统计检验评估及强塑性的标准偏差评估。结果表明,按优化工艺生产的9Cr 1Mo V Nb N厚壁无缝钢管显著优于1 050 ℃正火和790 ℃回火原工艺生产的厚壁无缝钢管,强塑性指标及其标准偏差已达到进口P91厚壁无缝钢管的水平,表明我国9Cr 1Mo V Nb N厚壁无缝钢管的制造技术已日趋成熟。
