Study On Microstructure And Performance Of CSP-Low Carbon Cold-rolled Sheet

The thesis regards CSP low carbon cold-rolled sheet DC03 steel of Lianyuan Iron and Steel Company as the research object, and analyses the effect of chemical composition , finishing temperature and coiling Temperature on microstructure and performance of products , the microstructures and texture of hot-rolled plate, cold-rolled plate and anneals plate were analysed,the evolution of microstructures and texture which were observed.the result offer basis for Lianyuan Iron and Steel Company on establishing technology of production of DC03 steel.The main research content of the thesis includes:1. The mechanics performance of the hot-rolled plate and cold-rolled plate of DC03 steel of Lianyuan Iron and Steel Company is statistically analysised.and compare with DQ grade products of some domestic company and analyse,which offer basis about the localization of deep-drawing plate of Lianyuan Iron and Steel Company in the like products in the whole country, realizing the defect and advantage of its products;2. Through statistical analysis to the data of production of CSP low carbon cold–rolled sheet of Lianyuan Iron and Steel Company.effects of chemical composition,coiling Temperature,finishing temperature on drawability of CSP low carbon cold–rolled sheet were studied,the technology system of refining and hot rolling for CQ and DQ products were optimized.3. The variation of the hot–rolled base plate microstructures under different coiling temperature and finishing temperature was observed, and the microstructrue,second-phase and texture of hot-rolled base plate,chill plate and annealed sheet for CSP low carbon cold-rolled sheet were also studied.The results show that, according to the control standard of chemical composition, increasing Al content,decreaseing C,Si,Mn content properly,and adopting high finishing temperature and low coiling temperature were propitious to the improvement of drawability. The microstructures of hot-rolled plate under low finishing temperature and high coiling temperature is unfavourable for drawability.The contact of microstructrue and texture between hot-rolled base plate,chill plate and annealed sheet exists,the annealing texture is effected by the chill plate texture.