Manufacturing method of press steel plate, manufacturing method of press part, steel plate, and evaluation method of elongation flange forming property

摘要

Problem to be solved: to set the appropriate heating treatment temperature and the heating range in accordance with the steel material, and to suppress the cracking of the extension flange portion more effectively.Solution: the method of manufacturing the press steel plate to be press processed.A shearing step 10A for shearing at least a portion of the end of the steel plate and a heating step 10B for heating a heating range preset in advance from the end portion at least a portion of the end portion of the sheared steel plate is provided.The heating temperature in the heating step 10B is less than 600.degree. C. or less than 800 degrees Celsius.AndBy heating it in the same heating condition as heating stepA ductility estimation step 10C for estimating the change of ductility of the heating part andBased on the estimation of the ductility estimation processWhen the ductility is estimated to be improved, the heating range is within the range of 3 mm or more from the end surface.When the ductility is estimated to decrease, the heating range determination step 10d and the heating range are within 6 mm from the end surface..Diagram