共查询到19条相似文献,搜索用时 48 毫秒
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针对340MPM机组(Multi-Stand Pipe Mill限动芯棒连轧管机组)芯棒服役过程建立三维有限元模型,研究芯棒在服役过程中温度场变化规律.同时,通过对热应力的研究,分析了芯棒热疲劳裂纹萌生机理及裂纹在芯棒内部的扩展规律.对比实测数据与模拟结果,认为所建立的有限元模型能够反映芯棒温度变化趋势.芯棒首次脱管后表面最高温度为630℃,此后经历三次反复的水冷降温和空冷返温过程,冷却结束后表面最高温度为98℃.脱管后,芯棒表面轴向和环向压缩热应力均达到900 MPa,第三次水冷结束时刻,轴向拉伸热应力达到186 MPa,环向拉伸热应力达到221 MPa.芯棒的拉压交变热应力使其表面出现热疲劳裂纹并逐渐扩展,环向裂纹扩展至距表面17.5mm深、轴向裂纹扩展至距表面20mm深时会显著受阻,热应力对轴向裂纹的促进作用强于环向裂纹. 相似文献
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半浮芯棒连轧管机自动控制系统 总被引:1,自引:0,他引:1
衡阳钢管厂半浮芯棒连轧管机是国内引进的首套具有当今世界先进水平的半浮芯棒连续轧管机组,其自动控制系统是由计算机,PLC,控制器构成。投运以来,系统运行稳定可靠,控制精度高,钢管质量好,取得了预期效果。 相似文献
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利用宝钢竹节攻关组的实测数据,对咬、抛钢阶段的前、后竹节形成过程作全面具体的讨论,阐述了竹节的形成机理及造成前、后竹节显明形态差异之根由。 相似文献
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在测定连轧管机各机架的力能参数基础上,对生产中出现的“电机负荷不均”现象进行了分析。提出了芯棒在机架之间传递能量的观点。认为芯棒的能量传递作用是导致连轧管机“电机负荷不均”的根本原因。并探讨了芯棒在机架之间传递能量的规律及其在实际生产中的应用。 相似文献
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简要介绍了我国钢管行业进入21世纪以来先后从国外引进的PQF三辊限动芯棒连轧管机与FQM三辊限动芯棒连轧管机的工艺特点和设备特征。通过对引进机组的对比分析,论证了其金属变形核心技术的一致性和生产过程中限动芯棒循回方式的差异性。其共同点是金属变形的核心技术、电气传动和自动化控制系统以及多层次的在线检测技术均代表了当今世界无缝钢管生产的顶尖技术和装备水平。 相似文献
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本文通过在连轧管过程中芯棒润滑剂对工艺参数影响的实测,探讨了轧制薄壁管的方法与措施,这对宝铜今后薄壁管的轧制及扩大品种,降低无缝钢管壁厚废品率和芯棒的消耗都有一定的参考价值。 相似文献
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Rajeev Baskiyar 《国际钢铁研究》2000,71(4):115-117
The thermal conditions during hot rolling operations can adversely affect the rolls’ service life and the quality of the rolled product. Analysis of the temperature profile of the rolls is an essential step towards the development of precise cooling systems to minimise their surface deterioration and thermal bending or camber. This paper makes an attempt at developing a finite element model for analysing the steady state temperature profile of rolls of varying dimensions. Rolls of large surface area exhibit greater differences in temperature between the surface and the interior as compared to those having smaller surface area and therefore make greater demands on the cooling system. 相似文献
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《Baosteel Technical Research》2010,(Z1):64
Based on the ABAQUS explicit dynamic simulation platform,the finite element model of single stand mill with restrained mandrel was adopted to research the influence of mandrel - roller velocity ratio (MRVR),mandrel friction and tension between stands on rolling force.The analysis results show that when the MRVR is lower than 1,the rolling force increases obviously with the increase of MRVR and reaches the peak value when the MRVR is about 1.The rolling force increase induced by the MRVR increase is the main reason of the formation of the bulge defect on the tube head and tail at the entering and exiting stage during tube continuous rolling process by full floating mandrel mill,which can be intensified by the increase of mandrel friction coefficient.The rolling force decreases with the increase of tension.As the tension is larger, the rolling force decrease amplitude is larger.The influence of backward tension on rolling force is greater than that of forward tension distinctly.Tension control can be used to decrease the rolling force increase induced by the MRVR increase,which is imposing tension at the same time when the MRVR increases,in order to improve even eliminate the bulge defect,and enhance the tube dimension precision. 相似文献
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转炉在服役过程中,存在炉壳热变形过大、耐火砖破裂等问题,直接影响到设备的安全运行,分析炉体的温度和应力分布,能为优化炉体冷却系统、避免应力集中提供支持。为此,建立包括非水冷式托圈、炉体与悬挂结构的转炉整体有限元模型,考虑炉体与托圈、悬挂之间的相互热辐射,采用ANSYS仿真软件研究炉体的稳态温度场,并对炉体的机械应力和热应力进行分析。结果表明,工作层炉衬热面温度为1 600℃时,炉壳的上锥段和炉身部位温度较高,最高可达435℃,接近炉壳的蠕变温度,有限元模拟结果与工业数据基本一致;炉体的热应力要远大于机械应力,炉衬的热面等效应力较大,易出现裂纹;炉壳的温度和应力分布在结构过渡处会有明显突变。研究结果可为炉体冷却和炉型设计提供理论依据。 相似文献
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MPM和PQF轧管工艺 总被引:1,自引:0,他引:1
连轧管机是生产无缝钢管的高效轧机,限动芯棒连轧管机代表着现代无缝钢管生产的先进技术,MPM和PQF同为限动芯棒连轧管工艺,对此2种连轧管工艺的特点进行了详细的分析. 相似文献
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R. K. Guduru Ph.D. R. O. Scattergood C. C. Koch K. L. Murty A. V. Nagasekhar Ph.D. 《Metallurgical and Materials Transactions A》2006,37(5):1477-1483
The authors present new experimental data for shear punch tests and tensile tests using four different materials. The correlation
between shear punch and tensile yield stresses must be established empirically, and the procedure for doing this is discussed.
The elastic-plastic deformation in a shear punch test develops gradually with increasing punch displacement and is often assumed
to be simple shear. This is examined using finite element analysis to simulate the development of plasticity during the early
stages of punch displacement. The simulation results are used to rationalize the empirically established yield stress correlations. 相似文献