Research On Formability Of Cold-Rolled Deep-Drawing Sheet Metal

As the fast developing of the auto industry, it gives more opportunities to the steel industry than before, especially the demanding on the sheet steel. The steels which supply to auto industry have high strength value or high deep-drawing. These two points require the steel holding formability well. Research on formability of cold-rolled deep-drawing sheet metal is necessary.In this thesis the cold-rolled deep-drawing sheet metal DC01, DC03, DC04and DC06, produced by Bengang Iron and Steel (Group) Company is studied. Using the BCS-50AR as a tool to analyze the formability of cold-rolled deep-drawing sheet metal. On the basis of microstructures and mechanical property, we study the influence of material formability. By way of lots of experiments, Research on test conditions influence of material formability summarizes disciplines.The contents of the study include the following main parts:(1) According to the microstructures and mechanical property of cold-rolled deep-drawing sheet metal, we can find out the affect of plastic forming.(2) The basic experiment includes the Erichsen test, Fukui test, earring test and KWI test. The factors which affect the formability of sheet metal were also referred in the research, especially the conditions of tests. Through many forming tests, we can get the best scheme. Using the best scheme can improve the success rate and get more accurate results.(3) The study of the conditions analyzes affect to the formability of cold-rolled deep-drawing sheet steel. The test conditions contain blank-holding force, the speed of test, load-control, the side of specimen, the die radius, lubricant and so on. Identify the causes of the change of test value. As a result, the blank-holding force has a relationship to auxetic type test, for example Erichsen and earring so on. In the test, the speed is slow, so it can’t change the material formability. Through the test we know that the load-control is necessary to the forming test. The side of specimen also affects the value of test. When do deep drawing test, the die radius affect the earring. Through the entire forming test, the lubricant can increase the specimen formability. (4) The forming limit diagram indicates the maximum strain limit of the material comprehensive. We get the FLD of DC06through the test, it can evaluation the DC06formability effective. Sum up experience and do a better job in the next test.