中厚板UFC-ACC过程控制系统的建立及冷却策略的制定

分析了UFC-ACC工艺的设计原理及特点,建立了中厚板UFC-ACC过程控制系统。在分析该系统功能及实现方式的同时,着重说明了模型计算系统的组成及计算原理。同时,对超快冷段冷却策略、层冷段冷却策略及两段协调策略进行了阐述。结合现场实测数据,得出该过程控制系统具有较好的计算稳定性及较高的计算精度,计算终冷温度与目标温度的偏差在4%以内,计算终冷温度与实测值的偏差在3.5%以内,可满足生产需要。     

Effects of Microstructure on CVN Impact Toughness in Thermomechanically Processed High Strength Microalloyed Steel

Investigation on the correlation between microstructure and CVN impact toughness is of practical importance for the microstructure design of high strength microalloyed steels. In this work, three steels with characteristic microstructures were produced by cooling path control, i.e., steel A with granular bainite (GB), steel B with polygonal ferrite (PF) and martensite-austenite (M-A) constituent, and steel C with the mixture of bainitic ferrite (BF), acicular ferrite (AF), and M-A constituent. Under the same alloy composition and controlled rolling, similar ductile-to-brittle transition temperatures were obtained for the three steels. Steel A achieved the highest upper shelf energy (USE), while large variation of impact absorbed energy has been observed in the ductile-to-brittle transition region. With apparently large-sized PF and M-A constituent, steel B shows the lowest USE and delamination phenomenon in the ductile-to-brittle transition region. Steel C exhibits an extended upper shelf region, intermediate USE, and the fastest decrease of impact absorbed energy in the ductile-to-brittle transition region. The detailed CVN impact behavior is studied and then linked to the microstructural features.     

Analysis of non-steady state slab edging in roughing trains by a three-dimensional rigid-plastic finite element method

Numerical simulation of the non-steady state deformation behavior around the head and tail ends during slab edging is carried out by the full three-dimensional rigid-plastic finite element method. The calculated shape of the slab edged, separating force and rolling torque are shown to be in good agreement with the experimental results found in the literature and the calculation precision is improved to a certain extent compared with previous works.     

辊式水平矫直对重轨断面尺寸的影响分析

 采用ANSYS/LS DYNA软件模拟了八辊复合矫直机水平矫直60 kg/m重轨过程,计算了矫直前后轨头宽度、轨底宽度和轨高的变化,并对60 kg/m重轨实际矫直前后的断面尺寸进行了测量。矫直后轨头宽度增加量在0.1~0.5 mm范围内所占比例约为82.9%,轨底宽度增加量在0.1~0.4 mm范围内所占比例约为68.6%,轨高减小量在0.2~0.6 mm范围内所占比例约为71.4%。模拟结果和实测断面尺寸的变化量基本吻合。矫直辊压下量和重轨弯曲度的减少,可以降低矫直对重轨断面尺寸的影响。     

低合金厚板的减量化轧制

 通过挖掘设备潜力,采用奥氏体再结晶区直接轧制+轧后快速冷却工艺在某宽厚板生产线上成功试制了60～85 mm厚Q345系列C Mn低成本厚板,Z向性能稳定达到Z35标准要求。试验结果表明,用该工艺生产低合金厚板可缩短2 min轧制时间,提高了机时产量,促进钢铁工业的可持续发展。     

梅钢1422热连轧机组上游机架工作辊辊形研究

 针对梅钢1422热连轧机组的某些冷轧料产品凸度超下限和某些品种钢产品凸度超上限进而严重影响凸度命中率的问题,应用热连轧机组凸度在上游机架控制的板形控制策略,对上游机架F1～F3原使用的CVC工作辊技术进行了深入分析和改进研究,提出一种新的工作辊辊形曲线,命名为MHW辊形。在运用ANSYS有限元软件对优化前后的辊形凸度调节能力进行了对比仿真后,将新辊形投入现场生产应用并使得机组的凸度命中率明显提高。     

中厚板冷却集管供水装置关键参数的研究

层流冷却过程中钢板均匀性控制是影响中厚板轧后冷却系统的重要因素。供水系统合理性设计是层流冷却系统实现钢板各向冷却均匀性的保障。对于层流冷却设备供水装置而言,不仅仅要提供足够的冷却水量确保层流冷却系统的冷却能力,而且要确保集管冷却水源的稳定性。针对集管供水装置建立了高位水箱到分流水箱水力学模型,通过迭代方法计算能够保障供水系统稳定性的最优输水管道的管径和高位水箱临界水位高度。     

Model Building of Backup Roller Diameter Effect Rate in 4-High Mill

Software for calculating the strip profile in 4-high hot rolling mill was developed using influence coefficient method. Regularity of backup roller diameter effect rate was studied systematically using the software. The results show that backup roller diameter effect rates decrease versus the increase of strip width, increase significantly versus the increase of backup roller diameter and obscurely increase versus the increase of reduction. The difference between backup roller diameter effect rate and it is reference value increases versus strip width increasing. When backup rollers diameter is set to be 1.64 m and strip width is 1.85 m, the error of strip profile calculated using the model of backup roller diameter effect rate reference value will be 3.55μm. Based on the results, reference values of roller diameter effect rate and six power polynomial fitting coefficients of modification coefficients were determined considering coherent parameters. The high precision model of backup roller diameter ef     

特厚钢板轧制缺陷压合临界条件物理模拟试验

由国内某厂提供的320 mm的有缺陷连铸坯,试样尺寸是160 mm×100 mm×180 mm,在东北大学轧制技 术及连轧自动化国家重点实验室轧制。模拟比为2.0,按平均压下率小、中、大,将试件分成3组,每组轧成3种不 同厚度的成品板,其中中等平均压下率是按缺陷临界压合条件制定,既粗轧道次满足动态临界几何条件 l/ h = 0.53。轧制后经超声波检验合格,验证了缺陷压合的临界条件。