Research On Microstructure And Properties Of DC04EK Enamel Sheet Steel And Process Development

Steel for porcelain enameling has been playing an important role in national economy, and is closely related with people’s lives, however its domestic research has fell behind. Steel for enameling demands not only high elongation, high value of n and r, but also excellent property for enamel. Production of this steel is preferable to adopt Bell-type Annealing (BA) with a view to promote the accumulation and growing of second-phase particle. Whereas as the request for automation and continuative of production line, continuous annealing (CA) has been slowly developing the trend.The topic develops production method of DC04EK steel for enameling applied in deep dropping by adding a little element on the base of drawing steel. Through hot rolling, cold rolling, BA and CA, the microscope and property, and the capacity of hydrogen storage of the experimental steel after annealing is emphasized. By comparing the advantage of both annealing method, make the optimum technology. The contents and presentation results of this thesis state as follows:(1) Considering the various elements in the role of enamel steel, determine the chemical composition of experimental steel by increasing the content of Mn, S, Ti based on general composition of stamping steel.(2) As for bell-type annealing, observe the effect of annealing temperature on property. With the increasing of annealing temperature, the property has been optimized and the texture has strengthened. The steel under annealing temperature of730℃turns out to be of the best property.(3) As for continuous annealing, research the effect of soaking temperature and time on the microscope, texture and property, then determine the optimal process. Ajustment of soaking temperatue is more effective on improving the property and enhancing y texture. The optimal technique is soaking on850℃for90s. (4) By comparing both annealing processes, focus on analysising the effect of process on microscope, texture and property. The microscope is mainly composed by ferrite, and lots of Ti4C2S2, MnS and Ti(N, C) disperse on the fracture surface. The precipitates size and volume fraction of BA is larger than that of CA. The strength of CA is slightly higher than that of BA, and both properties meet the requirement of DC04EK.(5) Test the formability and fish scale resistance, both steels can meet the requirement of DC04EK, and the capacity of hydrogen storage of steel after BA is superior to that after CA.(6) By comprehensive analysis of experiment results, the suitable process of hot rolling, cold rolling and annealing for producing DC04EK enamel sheet can be expoited.