Research On Surface Strengthening Of Shape Roll For Cold Rolling Strip

Shape meter is the core equipment to realize automatic flatness control.In recent years,great progress has been made in the research of cold rolled strip shape meter in our country.The whole roll wireless shape meter has been independently developed and successfully applied in industry.Many new scientific and technical problems have been encountered in the long and stable operation of the shape meter.One aspect is how to improve the surface hardness and wear resistance of the shape roll and prolong the service life of the shape meter.For this reason,this paper will study the surface strengthening of the whole roll wireless shape meter(roll body material is GCr15).Firstly,the surface of strip roll is strengthened by high frequency induction hardening process,and the specific process parameters of induction hardening are designed.The surface morphology of the roll body after induction quenching was analyzed by metallographic microscope,and the distribution of the axial and radial hardness of the roll body after induction quenching was analyzed by microhardness tester.The shortcomings of induction hardening process are summarized through practical problems in industrial application.Secondly,laser cladding wear-resistant material was used to strengthen the surface of the shape roll.Three different alloy powders were selected as cladding materials.The surface morphology and element content distribution characteristics of three different cladding materials were analyzed by optical microscopy,scanning electron microscopy and energy dispersive spectrometer.The axial and radial hardness distribution of rollers after cladding different materials was analyzed by microhardness tester.The bonding effect,surface uniformity and hardness of different coatings were discussed and summarized.Finally,the wear characteristics of roll surface under two different processes of induction hardening and laser cladding were studied.Wear experiments were carried out with friction and wear tester and laser confocal microscope.The friction coefficient and wear morphology of two surface strengthening processes under different loads and frequencies were analyzed.The optimum surface strengthening process was evaluated by wear rate.