共查询到20条相似文献,搜索用时 468 毫秒
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轧辊是轧钢生产中的重要工具。为了解决轧辊的易磨损、易断裂、热裂纹和剥落问题,我公司采用了激光技术对轧辊表面进行改性处理,以达到在原轧辊韧性不变的状态下,大幅度提高其表面硬度,提高其耐磨损能力,以满足轧钢生产对轧辊的要求。经实验室试验、中试实验和工业生产实践证明,该研究获得了成功。1实验室试验1.1实验方案为观察经激光改性处理后的轧辊表面硬度及金相组织的变化,从70Mn2铸钢、低NiCrMo铸铁成品轧辊表面取3cmx5cmx12cm试料。将部份试样用激光技术进行改性处理,部分不做改性处理,二者进行… 相似文献
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最近,日本各大钢铁公司都在热带精轧机上扩大高速钢轧辊的使用率。川崎钢铁公司在知多厂用生产成本较低的离心铸造法制造高速钢轧辊,并在千叶厂和水岛厂的热带轧机上使用。其使用结果如下:①轧辊单耗降低。千叶厂第二热轧厂的F1、F2精轧机原采用高铬钢轧辊,水岛厂热带厂的F5精轧机原采用镍铬钢轧辊。现采用离心铸造的高速钢轧辊后,千叶厂F1、F2轧机每磨损1mm轧辊的轧制量为过去的3.5~4倍,水岛厂F5轧机为过去的4~5倍。②轧辊表面粗糙度小。千叶厂对F2精轧机使用高速钢轧辊和高铭钢轧辊的表面粗糙度进行了比较… 相似文献
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日本神户钢铁公司为了解决因工作辊表面粗糙造成的麻点缺陷而影响产品表面质量的问题,研制成功在线用摄像机摄像,观察轧制中轧辊表面状态的装置,即轧辊监视器。该公司将轧辊监视器设置在热带精轧机的F2机架内,利用CCD摄像机可沿轧辊长度方向任意位置拍摄轧制中轧辊表面的静止图像,摄像成功率几乎达100%,可连续使用,并可将图像放大表示在显示器上。由于该公司开发的轧辊监视器可以在轧制过程中在恶劣条件(喷射水、润滑油、振动)下非接触地观察,监视高速旋转的轧辊表面,因此,利用该装置研究并搞清了加热炉出炉温度、轧制… 相似文献
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轧辊表面经滚痕加工形成辊面沟痕,如图1所示,在轧钢时可提高轧辊与金属间摩擦系数,可改善咬入条件。轧辊经滚痕冷加工后,表层得到强化,表面硬度提高,从而还可提高轧辊使用寿命。 相似文献
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针对采用抛丸毛化轧辊平整机平整后的马口铁基板上出现的批量色差亮线,分析了轧辊表面形貌及轧辊表面发生剥落的原因,提出除需保持机架内腔、工作辊和支撑辊表面洁净外,还需尽量减少抛丸次数,采用圆形或圆形与菱形混合丸料,可避免轧辊表面出现“层状翘起组织”,从而控制带钢表面的“亮线”缺陷。 相似文献
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最近,日本钢管公司京滨厂开发了半高速钢轧辊。这种轧辊虽用传统的磨具(氧化铝系材质)不能研磨,但采用与金刚石具有同样结晶结构的、硬度约为传统磨具2倍的CBN(立方氨化硼)磨具可进行研磨。该厂在带钢冷连轧机第5架轧机上试用了3种不同成分的半高速钢轧辊,这些轧辊的化学成分、硬度和特性示于表1。这3种半高速钢轧辊试用后结果如下:①轧辊的表面粗糙度和摩擦系数比5%Cr钢轧辊稍高,特别是半高速轧辊B随着轧制量的增加,其摩擦系数的降低率最小,②轧辊的磨损比5%Cr钢轧辊小得多。用半高速钢轧辊轧制216km带钢… 相似文献
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某厂生产的 6 0 Cr Mn Mo双曲线轧辊 ,该轧辊经调质和表淬后回火时出现了开裂 ,试验分析表明 :表淬工艺不当 ,整体淬火产生的复杂的组织和应力状态是导致轧辊开裂的直接原因。 相似文献
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A complex method involving a technology and equipment for spray quenching is used for improving the quality of the metal of
back-up rolls of high-load mills. The accelerated cooling by sprayed water in the process of final heat treatment of back-up
hot-rolling rolls increases the surface hardness, accelerates the structural transformations over the cross section, and reduces
the total heat-treatment time as compared to normalizing.
Translated from Metallovedenie i Termicheskaya Obrabotka Metallov, No. 8, pp. 2–4, August, 1997. 相似文献
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B. Podgornik S. Milanović J. Vižintin 《Journal of Materials Processing Technology》2010,210(8):1083-1088
The aim of this investigation was to determine the effect of different production operations and parameters on residual stress level in double-layer cast rolls. Using a hole-drilling method, residual stress depth distribution in surface layer was measured around and along the body of the double-layer cast roll after casting, heat treatment, turning and grinding. Furthermore, using different turning and grinding parameters (speed, feed), and heat treatment parameters (temperature, time), influence of these parameters on residual stress level and distribution was determined.Results of the investigation show that the conditions in the casting pit have an influence on the residual stress field generated in double-layer cast rolls, with surfaces exposed to faster cooling rates in general showing higher residual stress values. Very critical phase in rolls production is coarse grinding, which if not carried out properly will generate very high tensile stresses in the roll surface and cause surface cracking or even roll fracture. Heat treatment on the other hand results in uniform compressive residual stress field in the roll's surface. However, reduction in tempering time and especially increase in hardening temperature lead to increased residual stress level in the roll surface. Final machining of the roll surface further influences residual stress level in the roll. Increase in turning speed of up to 40% results in compressive residual stress increase of up to 60%, while less than 30% increase in feeding rate gives almost 100% increase in residual stress level. 相似文献
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由于支承辊辊身局部剥落或使用到设计临界尺寸使其报废,造成很大浪费.本文采用热处理再机械加工、大直径改小直径及镶套修复等技术对废旧锻钢支承辊进行二次利用,为企业节约成本,也符合可持续发展、节能降耗的国家政策. 相似文献
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Chunbo Cai Zesheng Ji Huajun Zhang 《Journal of Materials Engineering and Performance》2010,19(5):627-632
To improve the surface morphology, formability, and deep drawing properties of 1050 aluminum alloy sheets, laser-textured
rolls were used in cold rolling process. Effects of laser-textured rolls, comparing with conventional ones, on microstructure
and texture of aluminum alloys after rolling and following recrystallization were studied. In aluminum sheets processed by
laser-textured rolls and conventional rolls, microstructure and texture were similar after rolling, but significantly different
after recrystallization. Laser texturing process results in finer and inhomogeneous recrystallized grains. The recrystallization
texture of the specimen rolled with conventional roll has a major cube component and a minor R component. The intensity of
cube component increases with increasing annealing temperature. However, recrystallization texture of the specimen rolled
with laser-textured roller is much more random. The specimen shows that recrystallization texture has only a weak cube orientation
but strong rotated-cube orientation as well as a much higher fraction of random orientation. 相似文献
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结合高强度宽厚板矫直机需对工作辊与支承辊在使用中产生的辊间磨损进行补偿的要求,介绍了采用复合组合式碟簧对辊间磨损进行自动补偿的技术方案,并与通常采用的楔块调整方式进行了比较。 相似文献
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Guillermo García-Gil Rafael Cols 《International Journal of Machine Tools and Manufacture》2000,40(14):1977-1991
A series of temperature measurements was made on the surface of work rolls left to cool in air after they were extracted from hot and cold rolling steel strip mills. The information was fed into a mathematical model which was developed to compute the temperature distribution within the rolls at the moment of their extraction, which will correspond to that of the steady-state process. Measurements on three positions on the barrel length (close to either side and at the centre) were fitted into a second degree polynomial to calculate the heat flux. It was found that the rolls installed in the cold mills are subjected to a higher thermal load, as their cooling system only delivers at the entry side of the strip. It was possible to relate the magnitude of the expansion to the highest temperature recorded in each roll, a feature which can be critical in the cold mills investigated. It is concluded that this type of tool can be used to understand the phenomena behind shape defects in either cold or hot rolled strip. 相似文献
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A standard chamber batch furnace of the Severstal' plant has been modified for precision heat treatment of CCM rolls. The certification tests of a charge of rolls from steel 24KhM1F have shown the technical and economical advantages of the new design. 相似文献