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本文从提高我国输油、输气管线用热轧板卷的韧性出发,探讨了在热轧宽带钢连轧机上生产低碳高强度微合金X60~X65级管线钢的优化控制轧制与控制冷却工艺制度,研究了热变形过程中变形奥氏体的再结晶规律、轧后冷却过程中相变规律,以及整个加热、轧制、冷却、卷取过程中微合金元素碳、氮化物的固溶与析出行为。结果表明,该实验用钢的合理控轧控冷工艺为:奥氏体化温度为1200℃,粗轧区开轧温度为1150℃,终轧温度为1050℃;精轧区开轧温度为950℃,终轧温度为860℃,轧后冷却速度为15℃/s,卷取温度为550℃。采用上述工艺,宝钢生产的X60~X65级管线钢板的冲击韧性值提高了1倍以上,其综合性能达到或接近日本进口钢板的实物水平。 相似文献
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利用Gleeble-1500热力模拟试验机,研究了典型低碳钢在未变形及变形条件下的连续冷却过程的相变规律,并通过光学显微镜对连续冷却后的组织进行了详细观察和分析。结果表明:随着冷却速度的增加,铁素体相变温度降低,相变时间缩短,晶粒细化,贝氏体含量增多;变形加速了钢的连续冷却转变,使CCT曲线左移,贝氏体的临界冷却速度增加。 相似文献
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奥氏体状态对Mn-Cr齿轮钢连续冷却相变组织的影响 总被引:1,自引:0,他引:1
使用Gleeble1500热模拟试验机研究了成分(%)为:0.23C,0.74Mn,0.90Cr齿轮钢奥氏体晶粒尺寸和变形(真应变量0.4)对连续冷却相变组织的影响和连续转变冷却(CCT)曲线。实验结果表明,当齿轮钢未变形时,获得完全多边形铁素体 珠光体混合组织的临界冷速为0.5-1℃/s,冷速较快时,中温相变产物由贝氏体及针状铁素体组成;奥氏体变形时,多边形铁素体相变开始温度升高,获得完全多边形铁素体 珠光体混合组织冷速增大,为1—2℃/s,中温相变产物没有出现贝氏体,只有针状铁素体。 相似文献
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Effects of deformation mode, deformation temperature, deformation rate, cooling rate and slow- cooling stop temperature on the transformation behavior of hot- rolled microalloyed TRIP steel were studied by means of MMS- 300 thermomechanical simulator. The results show that for the samples subjected to the single or double pass deformation, ferrite transformation area is expanded, pearlite transformation area appears, and martensite transformation area disappears in the continuous cooling transformation diagrams. Transformation temperatures of Ar3, Bs and Bf decrease, diffusional transformation is prevented and intermediate temperature transformation is promoted with the increase of deformation temperature or cooling rate. When deformation temperature is 850??, transformation temperatures of Ar3, Bs and Bf increase, the amount of ferrite also increases, and the amount of bainite decreases in the microstructure with the increase of deformation rate. With the decrease of slow- cooling stop temperature, ferrite amount increases, ferrite grains grow and retained austenite amount first increases and then decreases. 相似文献
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Effects of Deformation on Bainite Transformation During Continuous Cooling of Low Carbon Steels 总被引:4,自引:0,他引:4
ted alot of interests of metallurgical researchers.Aswell known,the steels with ultra-fine grains havepoor work hardening ability and high yield ratio[1].This problem can be solved through complexstrengthening mechanism in which some bainite isintroduced to ferrite matrix with suitable grain size.So it is necessaryto studythe transformation of aus-tenite to bainite inlowcarbon steels during continu-ous cooling after deformation.Most of the research works[2-4]about the trans-formation fromauste… 相似文献
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Deformation affects the microstructure and morphology of the parent austenite, which affects the subsequent bainite transformation. The effects of ausforming on bainite transformation and microstructure were investigated by means of thermal simulation experiment, TEM and SEM etc. Different deformation temperatures and deformation strains were designed. The amount of bainitic transformation during isothermal holding and the volume fraction of retained austenite at room temperature were analyzed. The results show that the isothermal bainitic transformation is promoted by the deformation at 300?? and 400??. Moreover, the lower deformation temperature leads to larger amount of bainite. In addition, the volume fraction of retained austenite increases with the increase of the deformation strain, and more retained austenite can be obtained by decrease the deformation temperature. It indicates that deformation at lower temperature contributes to the mechanical stabilization of austenite. 相似文献
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YI Hai-long DU Lin-xiu WANG Guo-dong LIU Xiang-hua 《钢铁研究学报(英文版)》2006,13(3):36-39,67
Utilizing Gleeble-1500 thermomechanical simulator, the influences of hot deformation parameters on continuous cooling bainite transformation in Nb-microalloyed low carbon steel were investigated. The results indicate that bainite starting temperature decreases with raising cooling rate and increases with increasing deformation temperature. Deformation has an accelerative effect on the bainite transformation when the specimens are deformed at 950 ℃. When the deformation temperature increases, the effect of deformation on bainite starting temperature is weakened. The amount of bainite is influenced by strain, cooling rate, and deformation temperature. When the specimens are deformed below 900 ℃, equiaxed ferrites are promoted and the bainite transformation is suppressed. 相似文献
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The transformation behavior of Nb-V micro-alloyed low carbon austenite steel during continuous cooling was investigated through Gleeble-3800 themomechanical simulator and metallographic analysis. The experimental results show that the dynamic CCT diagrams shift to the left and upper compared with the static ones, the begin temperature of A????-Fe transformation is gradually lower with the increase of cooling rate. The high temperature deformation improves Ferrite and Pearlite transformation and decreases Ferrite transformation zone. When the cooling rate is lower, the deformation improves Bainite transformation; when the cooling rate is higher, the deformation restrains Bainite transformation. 相似文献
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XUYun-bo YUYong-mei LIUXianghua WANGGuo-dong 《钢铁研究学报(英文版)》2005,12(2):49-51
Thedeformation inducedferritetransformation (DIFT)inthelowtemperatureregioncanbeusedto effectivelyproduceultra finegrainedsteels[1-7]. Thedeformationleadstotheincreaseofstoredener gyandshortenstheincubationperiod.Abovethe pointAr3,ferritetransformationwi… 相似文献
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The hot deformation behaviors and the microstructural evolution of plain C-Mn steels with similar contents of C and Si but different contents of Mn have been investigated by compressive processing using Gleeble-1500 mechanical simulator.Influence of Mn and hot deformation on continuous cooling transformation of steels has been studied.The experimental results showed that deformation in austenite region accelerated transformation process,and the extent is dependent on the hot deformation and cooling conditions.The hot deformation would promote transformation process,but the increase of transformation temperature is dependent on Mn contents.The results have also shown that the effect of deformation on ferrite transformation becomes more obvious with the increase of Mn content at relatively low cooling rate. 相似文献
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变形工艺对微合金高强度钢组织的影响 总被引:1,自引:1,他引:0
在THERMECMASTOR-Z热模拟试验机上进行了一种微合金高强度钢在不同变形程度、变形速率、变形道次和冷却速度等工艺条件下的热模拟实验.分析比较了不同变形工艺参数对微合金高强度钢相变及组织的影响.实验结果表明,提高轧后的冷却速度使Ar3温度降低;变形速率越大相变开始温度越高;变形程度越大相变开始温度越高.增大变形程度,采用多道次轧制,轧后快速冷却,均有助于铁素体晶粒的细化和减少珠光体的含量.实验钢种的γ+α两相区的温度范围大于140 ℃. 相似文献