共查询到19条相似文献,搜索用时 140 毫秒
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CSP微合金钢混晶问题分析 总被引:6,自引:0,他引:6
讨论了CSP生产铌徽合金钢Q345C的化学成分和轧制工艺,并就其产生的混晶现象从理论和实践上加以分析,最后提出CSP生产铌微合金化钢板的有关建议。 相似文献
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利用光学显微镜、扫描电镜研究分析了CSP薄板坯连铸连轧线(CSP线)铁索体轧制工艺生产钢板的显微组织,通过实验对其力学性能和成形性能进行了研究,并与该生产线采用常规奥氏体轧制工艺生产钢板的组织性能进行比较。研究结果表明:CSP线铁素体轧制工艺生产的钢板组织较粗大,强度较低,塑性较好,且具有良好的成形性。 相似文献
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混晶条带是影响GH2132合金组织及性能稳定性的重要因素,因此针对合金冷拉棒材出现的混晶条带缺陷进行了试验研究。利用金相、EPMA、EBSD和TEM手段,结合热力学平衡相图与硬度测试,揭示了混晶条带的主要成因,并分析了其内部微观组织状态及混晶组织对显微硬度的影响。结果表明,混晶条带组织中细晶区晶粒尺寸普遍小于10 μm,粗晶区晶粒最大可超过60 μm,而元素偏析与冷拉变形是造成晶粒大小差异并形成混晶条带的原因。合金铸态组织中Ti、Mo、C、B元素均表现出正偏析,其中C、Ti元素的偏析程度较高,能够在枝晶间析出MC与M3B2相,并最终遗传至奥氏体晶界;晶界溶质富集不仅起到钉扎作用,阻止再结晶过程晶粒长大,还能够通过溶质拖拽作用降低晶界的迁移速率而阻碍晶界变形,最终溶质富集区域形成细晶区、贫化区域形成粗晶区,并沿合金棒材组织冷拉方向表现出混晶条带。另外,在冷拉变形过程中,由于晶体取向不一,在受同样拉拔力条件下晶粒变形的实际应变并不一致,这也会加剧混晶现象。微观组织观察显示冷变形后细晶区与粗晶区相比形变更为均匀,组织内平均位错密度更高,混晶区域内存在退火孪晶与形变孪晶,但细晶区孪晶密度更高。最终混晶区存在的晶界数量不同、位错密度变化、孪晶分布的梯度组织,导致细晶区显微硬度明显高于粗晶区的硬度梯度。 相似文献
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封勇 《金属材料与冶金工程》2010,38(2):25-27,33
利用光学显微镜、扫描电镜研究分析了CSP薄板坯连铸连轧线铁素体轧制工艺生产的钢板的显微组织,通过实验对其力学性能和成形性能进行了研究,并与该生产线采用常规奥氏体轧制工艺生产的钢板的组织性能进行了比较。研究结果表明:CSP线铁素体轧制工艺生产的钢板组织较粗大,强度较低,塑性较好,且具有良好的成形性。 相似文献
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An integrated process modelling system for simulating the microstructure evolution of Nb-microalloyed HSLA steel produced in CSP hot rolling process has been developed on the basis of the microstructure simulation and mechanical properties prediction technology. 3-D thermomechanical coupled finite element models for simulating hot strip rolling have been developed and the distribution of equivalent plastic strain through the thickness direction of the rolled material by CSP roiling was obtained. Thus the distribution of temperature, strain and strain rate through the thickness of the steel stocks, as well as the microstructure evolution during hot rolling of X60 line pipe steel strip has been investigated by using the developed integrated process modelling system. In addition, the determination and op-timization of controllable process parameters during CSP hot strip rolling for the Nb-microalloyed X60 line pipe steel have been implemented, and control strategies such as adopting larger pass reduction in the first stand, arranging ap-propriate pass interval times and proper rolling speed, to reduce or eliminate mixed grain microstructure of Nb micro-alloyed strip in CSP processing have been proposed. 相似文献
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Mathematical Modelling on the Microstructure Evolution of X60 Line Pipe Steel during CSP Hot Rolling
An integrated process modelling system for simulating the microstructure evolution of Nb-microalloyed HSLA steel produced in CSP hot rolling process has been developed on the basis of the microstructure simulation and mechanical properties prediction technology. Thermo-mechanical coupled finite element models for simulating hot strip rolling have been developed and the distribution of equivalent plastic strain through the thickness direction in the rolled material of CSP rolling was carried out. Thus the distribution of temperature, strain and strain rate through the thickness of the steel stocks, as well as the microstructure evolution during hot rolling of X60 line pipe steel strip have been investigated by using the developed integrated process modelling system. In addition the determination and optimization of controllable process parameters during CSP hot strip rolling for the Nb-microalloyed X60 line pipe steel have been implemented, and control strategies such as adopting larger pass reduction in the first stand, and arranging appropriate pass interval times and proper rolling speed, to reduce or eliminate mixed-grains microstructure of Nb microalloyed strip in CSP processing have been proposed. 相似文献
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Present study concerns the effect of deformation and heat treatment on the microstructure and mechanical properties of a duplex
stainless steel. While hot rolling causes the coarse distribution of the constituent phases (ferrite and austenite), 50% cold
rolling results into the elongated and splintered two — phase structure. Supersaturated ferrite structure established by water
quenching from 1300°C results into the strengthening due to the formation of fine dispersed austenite precipitates within
ferrite grain after isothermal heat treatment (1000°C, 0.5 hour). Duplex structure consisting of ferrite and austenite in
a fine-grained form is obtained after isothermal heat treatment of cold rolled sample. Cold deformed and heat treated steel
exhibits best combination of strength and ductility among all the investigated steel samples. 相似文献
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热轧相变过程变形抗力模型研究与开发 总被引:1,自引:0,他引:1
对精轧阶段存在相变的热轧钢种,因变形抗力随轧制温度的变化规律与常规的奥氏体轧制钢种显著不同,使得传统变形抗力模型的预报误差较大,严重影响这类钢种的轧制稳定性。为此,研发了一种热轧相变过程变形抗力模型,通过在原变形抗力模型基础上添加一个新的相变趋势项,该修正项为轧制温度的二次多项式函数,并根据钢种分类来精细优化适应不同钢种轧制的多项式待定参数。该模型目前已成功应用于涟钢CSP热连轧生产线变形抗力在线计算,实际生产应用表明,新模型上线后,变形抗力与轧制力的预报精度显著提高,轧制力模型预报误差12%以内的比例从83.3%提高到96.7%,满足了热连轧精轧相变带钢的稳定生产要求。 相似文献
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Society demands high strength and environmental conscious steel and our solution is ultra fine grained steel without any rare earth alloy. We developed mathematical modelling for microstructure evolution and characterized rolling condition for ultra fine grained plain carbon steel in the tandem hot strip mill. We constructed a new tandem hot strip mill rolled at heavy reduction and low temperature in the last 3 stands in the finishing train. We produced ultra fine grained plain carbon strip with grain size of 3 microns. This steel has 30% improved strength and better formability compared to the conventional schedule rolling steel. 相似文献