Mill fault repair

Source:Jiangyin Lineng|Date: 2017-12-25| Hits

　　Due to the poor working conditions of the rolling mill, during the working process, the rolling cooling water encounters the red billet rapidly atomized, the iron oxide powder falling off from the surface of the billet is jetted to the periphery, and the roll passes the bearing seat to the frame arch Big impact, so that the mill mill arch inside the window surface, the bottom surface of the arch of the mill there are varying degrees of corrosion and wear, the mill stand and the roll stand gap is difficult to effectively control the management, often appear mill stand and roll chock gap Exceeds the management limit phenomenon. Mill gap increases the mill mill worsens the main drive system conditions, so that the main transmission vibration impact, prone to slipping steel ingot, affecting the shape of the control, the product quality has a significant impact. [2]
　　The vast majority of mill torch material for the ordinary steel castings, in the long service surface of the window vulnerable to corrosion and wear and tear caused by the deterioration of working conditions. The method of on-line machining is usually used to repair the archway, that is, the material is removed by machining, the damaged contact surface of the archway surface is cleared, and the enlarged size is compensated by increasing the thickness of the backing board. This repair method is simple and convenient operation, but did not change the nature of the arch surface, after a period of time the arch surface will be subject to corrosion and wear failure, and multiple machining will have an adverse effect on the strength and stiffness of the arch. Taking into account the mill's sensitivity to stiffness, the margin for processing is small, the repair method can only be an expedient measure. The use of manual arc welding can recover machined to remove the material to expand the size, but in such a rigid structure for large-area electric arc welding, may cause deformation of the arch structure. If the structure is distorted and destabilized it will be fatal and can no longer be rectified, something that the factory will never allow to happen. So the repair method will bring greater risk, generally not be used.
　　Today, polymer composite materials can be used to solve the wear mill mill. Polymer composite repair materials have excellent adhesion, can be firmly attached to the surface of the metal substrate, long-term work without falling off; the product itself has a high compressive strength, even up to 1900 tons of rolling force, the material Will not damage; unique polymer structure to give the material good impact resistance, can absorb the impact of the bearing on the arch, to avoid wear and tear; at the same time the product has good corrosion resistance, the arch can be protected from cooling water Erosion. The use of special materials repair mill arch wear, do not remove the material, does not affect the overall strength and stiffness of the arch, but also no deformation caused by welding stress, as the business is a good solution to the problem can not be solved for many years.