一种冷床快速移送装置

介绍了石钢特殊钢连轧生产线上设计与改造的一种冷床快速移动装置,该装置布置在步进式倍尺冷床间,能把成组的棒材快速地从冷床输入端移送至输出辊道上,满足了特殊钢不同收集温度的要求。     

大规格特殊钢棒材连轧生产线设备改造

分析了石钢公司第一轧钢厂大规格特殊钢棒材连轧生产线设备存在的问题并进行了创新性改造,解决了连轧机接轴能力不足、棒材不易上冷床、砂轮锯夹紧装置故障多、棒材易在辊道上产生划伤等问题,满足了生产工艺要求,降低了故障时间和设备维护费用。     

无缝钢管生产线冷床及选型

冷床是无缝钢管生产线上必不可少的设备,冷床的形式有多种,可根据生产需求的不同进行选择.总结了单链冷床、双链冷床、新型链式冷床、步进齿条式冷床、螺杆式冷床等各种冷床的优缺点,介绍了无缝钢管生产线上各种冷床的结构、工作原理及特点,为用户选择和设计冷床提供了参考.     

改变取样方式对HRB400热轧带肋钢筋物理性能的影响及应用

通过两种不同取样方式对HRB400热轧带肋钢筋物理性能的影响分析，表明在精轧出成品后立即在冷床上取物理试样与正常缓慢空冷取物理试样两者物理性能相差不大．为此在实践中加以应用，采取在冷床上快速取样试验快速反馈结果，提高了试验效率，指导了生产及时进行操作调整。     

特殊钢小方坯连铸机工艺设备特点和热调试简况

上钢五厂从丹涅利公司引进的四机四流特殊钢方坯连铸机,在设备设置上如大包回转、中包小车、二冷水控制、切割装置、冷床及断面更换方面都有其特点,结晶器和二冷凝固末端都配备有电磁搅拌装置,结晶器钢液面自动控制装置与通常采用的钴60控制方法不同,是应用光学探测原理制成。对改造我国现有同类型的连铸机,可资借鉴。     

棒线冷床自动时序周期控制实现与应用

介绍棒线冷床自动控制周期采用时序控制,建立速度控制与时序控制的关系,控制冷床角度,实现位置和周期控制,由两台电机同步驱动冷床。适应为提高生产效率而提高轧制节奏和多切分轧制的需求,适应快速轧制和切分多线轧制,实现冷床具备快速冷却、动作周期短、精准计数、轧件质量提高的功能。     

液压冷床在大棒生产线的应用

介绍了一种应用于大棒材生产线的液压冷床,叙述了冷床的结构,介绍了不同规格产品在冷床上运行的原理,最后计算验证了冷床的承载能力。该冷床在石家庄钢铁有限公司营口生产线上得到成功应用。     

中小型棒材车间步进式冷床长度的计算

介绍了年产100万t的某棒材中小型轧钢车间冷床的工艺尺寸计算和冷却能力的校核。对棒材在冷床上的冷却主要考虑热辐射,采用波尔茨曼公式计算棒材冷却所需时间,求出冷床长度,并将该时间与棒材在冷床上实际通过的时间进行比较,校核了冷床长度。     

步进式冷床轧件制动探讨

小型材在冷床输入端的制动是步进式齿条冷床的一个重点课题.分析了对轧件上冷床制动过程,探讨了制动距离的具体计算公式,对确定轧线长度及对冷床制动板动作周期各时间段分配均有参考价值.     

螺纹钢冷床头部弯曲分析与措施

中南股份棒材三号线于2022年1月完成改造热试，由于工艺与设备的改变导致成品上冷床后，在冷床头部出现弯曲现象，严重制约了冷床的工作能力与冷飞剪的剪切效率。针对螺纹钢上冷床后弯曲现象，从加热温度、轧后冷却、倍尺剪切等因素分析，制定方案，并成功改善了冷床弯钢现象。     

Effect of Ultra Fast Cooling on the Alloy Cost Reduction of the X80 Pipeline Steel

The microstructures and mechanical properties of X80 pipeline steels produced by both novel ultra fast cooling and conventional‐accelerated continuous cooling modes are investigated. Results showed that different levels of Mo addition had a remarkable effect on the microstructures and mechanical properties of the investigated pipeline steels. The proeutectoid ferrite and pearlite formation is inhibited in the high‐Mo steel and acicular ferrite is obtained over a wide range of cooling rates, whereas the dominant acicular ferrite microstructure can only be obtained when the cooling rates reach up to 5 C s^?1. Very similar microstructures and mechanical properties are obtained in the low‐Mo steel produced with ultra fast cooling and in the high‐Mo steel produced by the conventional‐accelerated continuous cooling. It was proved by simulation and industrial trials that high‐strength low‐alloy steels such as pipeline steels, can be produced using the novel ultra fast cooling which also reduce alloy cost.

     

棒材冷床上料装置电机的选择及校核

冷床上料装置是棒材生产线的重要设备,放置于分段飞剪后的冷床前面,需快速频繁地起动和制动。分析了一种冷床上料装置的工作原理及工作过程,对电机的工作时间和发热进行了校验计算,证明所选用的电机既可保证频繁起制动的时间要求,又不会因此而引起电机过热,完全满足使用要求。     

近年来低合金高强度钢的进展

 从洁净钢生产、薄板坯连铸连轧无头轧制、薄带铸轧以及以快速冷却为核心的TMCP工艺等几个方面介绍了HSLA钢生产工艺技术的最新发展,并系统介绍了汽车用钢、船舶及海洋工程用钢、管线钢、建筑结构钢、核电用钢、压力容器用钢、工程机械用钢及集装箱用钢等行业所用的HSLA钢品种开发方面新进展。认为未来HSLA钢将向高强、高性能和低成本方向发展,对HSLA钢的发展有指导作用。     

Development of Dual Phase and Multiphase High Strength Steels by Using a New Cooling Technology: The Howaq‐Twice Process

In order to develop low alloy dual and multiphase high strength steels, CRM and Arcelor implemented the Howaq‐twice process in a continuous annealing line. This new equipment combines a slow primary cooling with a fast secondary cooling. Various cooling strategies were investigated in regard to microstructure and mechanical properties of low alloyed steels. Depending on the cooling rate and the quenching temperature, the microstructure varied between fully martensitic, ferritic‐martensitic, and ferritic‐martensitic‐bainitic. The associated tensile strengths reached from 720 to 1100 MPa.     

3800mm炉卷生产线冷床设计主要问题探讨

就3 800 mm炉卷生产线冷床设计中的几个主要问题进行了探讨,确定了冷床的型式、上下料装置的型式及冷床的润滑方式,计算出了需要的冷床面积,并给出了建议的冷床尺寸。     

Study of TRIP-Aided Bainitic Ferritic Steels Produced by Hot Press Forming

A study is reported to produce high strength ductile steels by controlled cooling following hot press forming, instead of quenching, as is practiced in the traditional press hardened steels. Heat treatments of several specially designed low carbon steels were carried out by interrupting the fast cooling from the austenization temperature at temperatures between T ₀ and Ms and then cooling in controlled rates to room temperature. The effect of the interrupt temperature and the cooling rate afterward on the microstructures and tensile properties was studied. The microstructures were characterized using dilatometry, optical microscopy, X-ray diffraction, and TEM. A multi-phase microstructure including bainite, martensite, and retained austenite was obtained in the simulated hot press forming process. Volume fraction bainite was found to increase with an increase in interrupt temperature and a decrease in cooling rate. Structure–property correlations of the studied steels heat treated at different conditions were developed. Improved tensile properties were obtained by controlling the interrupt temperature and cooling rate which produced an optimum bainite content of 60 to 75 pct and retained austenite. Unfortunately, the bainite in the simulated samples was not completely carbide free even though the steels contained about 1.6 wt pct of Si.     

升降裙板在轧钢收集区的应用

介绍了莱钢中小型车间轧线到冷床一组带升降裙板的收集辊道的结构和功能,该辊道控制思想严谨,使设备动作迅速准确,能把轧线上高速轧制的钢材准确收集到冷床上,设备既简单而且应用非常方便。     

连轧中型生产线冷床上料装置改造

分析了连轧中型生产线冷床上料装置运行中存在的问题,对油缸支架、油缸销轴做了改进,在冷床盖板处增设导向轮装置,在裙板上增设支撑块,弥补了冷床上料装置原设计的不足,减少了设备故障停机时间,提高了机时产量,降低了职工的劳动强度及生产成本.     

Continuous cooling transformation kinetics of thermomechanically worked low-carbon austenite

Continuous cooling transformation diagrams were determined for molybdenum-boron steels containing 0.24, 0.4, and 0.66 pct Mo with 0.1 pct C, and also 0.4 pct Mo with 0.2 pct C, after thermomechanically working by compressive deformation to 12, 25, and 50 pct reduction at 830°C (1525°F), as well as for the steels in the underformed condition. In underformed specimens, higher carbon or molybdenum decreased the limiting cooling rate for the avoidance of polygonal ferrite formation. The same was true for deformed specimens, although increased deformation raised the limiting cooling rates of all compositions. The limiting cooling rate for polygonal ferrite formation increased exponentially with austenite, deformation, as measured by true strain. Thermomechanical working also raised bainite start temperatures at fast cooling rates and caused small increases in martensite start temperatures.     

Multiphase microstructure in steel bars produced by dieless drawing

In the dieless drawing technology the drawing dies are replaced by a heating device, generally by an induction coil. Bars of different cross-sections, round or even rectangular, with varying dimensions along the length can be produced. By using a cooling box in connection with the heating device this deformation process may also be employed for a thermomechanical treatment of steels. The special cooling strategy with low cooling rates at high temperatures (during ferrite formation) and higher cooling rates at lower temperatures favours the formation of multiphase microstructures (ferrite - bainite/martensite) with a low yield strength but a strong work hardening effect. The experiments were carried out on rods with a diameter of 16 mm of a plain low carbon steel (0.1%C, 0.7%Mn). The specimens were locally heated up to the maximum temperature ?_max that initiates the dieless drawing process, and subsequently cooled with different coolants. The change in yield strength and tensile strength and the corresponding change in the ratio of both could be achieved by variation of ?_max and the cooling conditions. The multiphase microstructure with desired mechanical properties was produced at a strain of about more than 0.45 within the region of ?_max ≈ 900–1000°C and a finale cooling rate of about 20 K/s.