Large Ring Rolling Continuous Casting Forming New Technology And Process Control Study

With the widely application of the large rings, the production process ofring has a large development and improvement. Basing on casting rollingcomposite forming technology, the object of this study is to put forward a kindof high efficiency and energy saving technology—casting-rolling continuouslyforming, the core idea of this technology is to use slab heat for hot rollingprocess directly, which can shorten the production cycle and improve the energyefficiency meanwhile. In this work, numerical simulation and experimentalstudy are employed to determine various process parameters for productionprocess control.The research firstly utilizes the alloy phase diagram and thermal physicalproperty parameters database of42CrMo on the theory which analysis formmetal solidification on42CrMo steel. Then using casting simulation software—ProCAST, established the geometric model and material model for finiteelement simulation of centrifugal casting, take the analysis of temperature fieldand stress field of the casting process, the aim is to assure the casting processparameters. Finally, determined the heating temperature and holding time duringthe transfer process of ring after casting the mold, the alloy dynamic change ruleis gotten from high temperature metallographic experiment research. Thenobtained castings meet the requirement of rolling. Experimental observationshows are as follows:(1)The material model and the stress model of as-cast42CrMo aresimulated from ProCAST software.(2)Using the Jmatpro software simulated the alloy phase diagram of as-cast42CrMo steel. Combined theory with industrial practice to confirm smeltingtemperature which is1700℃, and the smelting time is3.5~4h.(3)Simulated the casting filling process and solidification process ofcentrifugal casting, took analysis of the filling process of casting, thetemperature field and stress field change before and after the mold, so that can make a certain pouring temperature of42CrMo ring. The temperature is1520℃, the mold temperature is1050℃.(4)Employing the high temperature heating stage experiment to researchthe organization’s changing rules of42CrMo alloy under the high temperature.When the heating temperature is1050℃, holding time is10minutes, small andhomogeneous alloy grains were obtained. The experimental results confirm tothe requirement of rolling grain size.(5)In conclusion that the process of casting-rolling continuously forming ofrings are as follows: smelting in the electric arc furnace(EAF)â†'casting in thevertical centrifugal casting furnaceâ†'casting the moldâ†'to clean up the surfacethough manipulator to the cleaning placeâ†'in the heating furnace(heatpreservation)â†'to the ring rolling machine by manipulator.