采用Thermo-Calc热力学计算软件对Nb-Ti-IF钢在0～1600℃存在的平衡析出相进行了热力学计算,讨论了合金元素Nb和Ti含量对含Nb、Ti平衡析出相的影响。此外,对Fe Ti P相的平衡析出进行了热力学计算,并将计算与显微分析结果进行对比。结果...采用Thermo-Calc热力学计算软件对Nb-Ti-IF钢在0～1600℃存在的平衡析出相进行了热力学计算,讨论了合金元素Nb和Ti含量对含Nb、Ti平衡析出相的影响。此外,对Fe Ti P相的平衡析出进行了热力学计算,并将计算与显微分析结果进行对比。结果表明,Nb-Ti-IF钢中平衡析出相主要有：FCC_A1#1、FCC_A1#2、LAVES_PHASE_C14、Ti4C2S2、Mn S及M3P。Ti含量对各含Ti析出相的影响规律如下：≥0.045%Ti,Ti含量变化对FCC_A1#1相的析出几乎没有影响;〈0.045%Ti,Ti含量变化对FCC_A1#1相的析出开始产生较明显的影响。≥0.05%Ti,Ti含量变化对Ti4C2S2相的析出影响较小,而当〈0.05%Ti时,Ti含量对Ti4C2S2相的析出影响十分明显。合金元素Nb、Ti的最佳添加量分别为0.02%和0.05%。展开更多
The structure and texture formation for single cold rolling （SCR） with annealing and double cold rolling （DCR） with annealing were investigated based on optical microscope and X-ray diffraction （XRD） with a Nb＋...The structure and texture formation for single cold rolling （SCR） with annealing and double cold rolling （DCR） with annealing were investigated based on optical microscope and X-ray diffraction （XRD） with a Nb＋Ti bearing interstitial free （IF） steel. The results indicated that DCR recrystallization grain was smaller than that of SCR sample and double cold rolling process resulted in better mechanical properties than those resulted from single cold rolling process with the same total reduction conducted. The plastic strain ratio increases from 2.23 for single cold rolling process to 3.2 for double rolling process. The fish-bone structure was observed in all SCR and DCR samples. DCR annealed sample is made up of equiaxed grains of almost uniform size, whereas SCR annealed sample shows a duplex grain structure, consisting of both large and small-sized grains. （Ti＋Nb）C and Fe（Ti＋Nb）P type precipitates were very rarely observed in SCR annealed and DCR annealed steels. The intensity of {111}∥ND for the DCR annealing was higher than that for SCR annealing.展开更多
The Nb-Ti microalloyed high strength IF steel sheet was used to study the effect of annealing temperature on the microstructures,mechanical properties and textures.The experimental results show that experimental steel...The Nb-Ti microalloyed high strength IF steel sheet was used to study the effect of annealing temperature on the microstructures,mechanical properties and textures.The experimental results show that experimental steel is incomplete recrystallization at 750℃ annealing,but complete recrystallization from 780℃ to 870℃ under experimental conditions.When the annealing temperature was increased,the yield strength and tensile strength would gradually reduce,the plastic strain ratio and yield point elongation would gradually increase.The yield strength,tensile strength,elongation,the plastic strain ratio and the strain hardening exponent were approximate 300MPa,410MPa,36.5%,1.7 and 0.22 respectively under annealing temperature 810℃ to 840℃.When the annealing temperature was increased,the α-textures and γ-textures were gradually weakened,and the α-textures have a trend to {111} texture.Therefore,the suggestion of the optimal recrystallization annealing temperature is about 810℃ to 840℃ in industrial production.展开更多
文摘采用Thermo-Calc热力学计算软件对Nb-Ti-IF钢在0～1600℃存在的平衡析出相进行了热力学计算,讨论了合金元素Nb和Ti含量对含Nb、Ti平衡析出相的影响。此外,对Fe Ti P相的平衡析出进行了热力学计算,并将计算与显微分析结果进行对比。结果表明,Nb-Ti-IF钢中平衡析出相主要有：FCC_A1#1、FCC_A1#2、LAVES_PHASE_C14、Ti4C2S2、Mn S及M3P。Ti含量对各含Ti析出相的影响规律如下：≥0.045%Ti,Ti含量变化对FCC_A1#1相的析出几乎没有影响;〈0.045%Ti,Ti含量变化对FCC_A1#1相的析出开始产生较明显的影响。≥0.05%Ti,Ti含量变化对Ti4C2S2相的析出影响较小,而当〈0.05%Ti时,Ti含量对Ti4C2S2相的析出影响十分明显。合金元素Nb、Ti的最佳添加量分别为0.02%和0.05%。
基金Sponsored by National Natural Science Foundation of China(51174020)Fundamental Research Funds for Central Universities of China(FRF-SD-12-010A)
文摘The structure and texture formation for single cold rolling （SCR） with annealing and double cold rolling （DCR） with annealing were investigated based on optical microscope and X-ray diffraction （XRD） with a Nb＋Ti bearing interstitial free （IF） steel. The results indicated that DCR recrystallization grain was smaller than that of SCR sample and double cold rolling process resulted in better mechanical properties than those resulted from single cold rolling process with the same total reduction conducted. The plastic strain ratio increases from 2.23 for single cold rolling process to 3.2 for double rolling process. The fish-bone structure was observed in all SCR and DCR samples. DCR annealed sample is made up of equiaxed grains of almost uniform size, whereas SCR annealed sample shows a duplex grain structure, consisting of both large and small-sized grains. （Ti＋Nb）C and Fe（Ti＋Nb）P type precipitates were very rarely observed in SCR annealed and DCR annealed steels. The intensity of {111}∥ND for the DCR annealing was higher than that for SCR annealing.
文摘The Nb-Ti microalloyed high strength IF steel sheet was used to study the effect of annealing temperature on the microstructures,mechanical properties and textures.The experimental results show that experimental steel is incomplete recrystallization at 750℃ annealing,but complete recrystallization from 780℃ to 870℃ under experimental conditions.When the annealing temperature was increased,the yield strength and tensile strength would gradually reduce,the plastic strain ratio and yield point elongation would gradually increase.The yield strength,tensile strength,elongation,the plastic strain ratio and the strain hardening exponent were approximate 300MPa,410MPa,36.5%,1.7 and 0.22 respectively under annealing temperature 810℃ to 840℃.When the annealing temperature was increased,the α-textures and γ-textures were gradually weakened,and the α-textures have a trend to {111} texture.Therefore,the suggestion of the optimal recrystallization annealing temperature is about 810℃ to 840℃ in industrial production.
