Failure Mechanism And Life Study On Drum Segment Of Hot Rolling Coiler

As a high-tech steel products, the output and property of hot rolled strip reflect thelevel of iron and steel industry of a country. In the process of production, improve thestabilization of device of rolling line is an important condition of safeguard on productquality. But due to various factors, devices of hot rolling line often occurs failure damage,come to have an affect on product quality and production efficiency. Therefore, carry outfailure mechanics analysis on part which tends to be destroyed and put forwardcorresponding optimization measures is one of the hot research on production of strip atpresent.Segment is one of key components of hot rolling coiler, wear failures and crackfailures usually happen in working process. This paper takes the failure mechanics ofsegment as research object, analyze the wear mechanism and crack mechanism of parts,put forward the judging criterion of wear failure and crack extend out of control, establishwear loss model and life prediction model, intensive research influencing regularities ofexternal conditions and internal structure on strength character of materials. On that basis,put forward optimization measures of relief wear and fracture-arrest, in the end providetheoretical foundation and practical reference for extend the working life of segment andimprove the working stabilization of hot rolling coiler.Establish dynamics finite element model, simulate the radial pressure of segment inworking process, corresponding with many existing calculation model, in the enddetermined the applicability of ZHOU Guo-ying formula on radial pressure calculation ofhot rolling coiler, lay a foundation intensive force analysis.Establish thermal–mechanical coupling model, simulate the regulation oftemperature field, stress field and deformation distribution in each phase, gets theconcrete form of temperature uneven distribution, deformation uneven distribution andstress concentration, demarcate research range and provide computation basis for strengthcheck and failure analysis.Put forward wear failure judging criterion, establish wear calculation model and life prediction model, simulates fiction and wear behavior under special working condition byexperimental, through observe and measure to worn specimen, judge out the wearmechanism in coiling process and the influence of external loading conditions to wearmechanism transformation. Furthermore, change the parameters setting in experimental,research the wear resistance of materials, gets the influence regularity of normal load,ambient temperature and sliding speed to wear performance, provide theoretical guidancefor setting coiling process and cooling process reasonable.Research the generation and extending mechanism of crack, judge out the propertyof failure crack and fracture mechanism through fracture analysis. Consider the influenceof material properties, structural shape and application environment, calculate the fracturetoughness and stress field intensity of crack tip, put forward the judging criterion of crackextending out of control, get the reason of crack failure, the conclusion can used as designbasis of process improvement and structure optimization.Perform optimization on extending working life on the basis of failure mechanics,provide optimization measures take controlling the deformation uneven distribution andstress concentration as the goal. Divided into two groups of structure and cooling process,which structure optimization include adjustment of distortion allowance and degree offreedom, and the cooling process optimization mainly distribute time to homogenizing thestress distribution. The results of simulation and industrial verification show that theoptimizations can get favorable effects on relief the level of wear loss, inhibit thegeneration and extending of crack, in the end attain the expected purpose of extendingworking life.On the whole, the research on failure mechanics and extending working lifeoptimization of segment of hot rolling coiler, consider the influence of many factors suchas coiling process institution, material properties, manufacturing process and structuralshape, having a certain theoretical value and practical reference significance on extendingworking life of segment, improve the product quality and production efficiency in hotrolling mill.