METALLURGICAL APPLICATION TO WORK AND （冶金应用程序来工作）.pdf

METALLURGICAL APPLICATION TO WORK AND BACK UP ROLLS FOR HOT COLD ROLLING OF FLAT PRODUCTS. Written by: Gonzalez, J*; Llano, J*; García, J*. Rolling mills are increasingly demanding rolls capable to maintain the shape and profile much longer with the aim to extend the length of campaigns. The state of the surface is one of the criteria determining the roll change. With the aim to satisfy the mill requirements it is necessary to pay attention to the Kinetic of oxidation, hot hardness increase in the matrix and the morphology of the different type of carbides. Key words: Hot rolling, Cold Rolling, Kinetic of Oxidation, Hot Hardness, morphology of carbides. International Workshop on “Rolls for Flat Rolling of Steel” at JSW Steel, Bellary on 26th th and 27 of February 2007 *Fundición Nodular, S.A., 33420 Lugones, Spain. 1. PREFACE: Both for cold and hot rolling numerous studies are being carried out and starting up new forms of measurement such as: Increase of the quality level, Improve of productivity, Reduce the production costs by means of reliable equipment. Rolling mills value the rolls by the cost of uses and the excellent quality of the obtained surface on the rolled product; the present exposition has various objectives: Rolling mills expectations, rappel of stresses experienced by rolls rappel of different degradations, balance of used qualities, new metallurgical and technological directions in the manufacturing of rolls: in this exposition it is possible to see how the rolls display an extremely high level in alloy elements: this leads to a new beginning of the rolls metallurgy, where the quality essentially depends on the relations between the different parameters of manufacturing and the structural characteristics related to germination: