Investigation of the process of aging cold rolled and hot dip rolled products of high-strength automotive steels for cold deformation

Abstract

The paper studied the aging process of cold rolled and hot dip rolled products of high-strength automotive steels have good formability, weldability and resistance to dents. The article presents data on the timing guarantees the mechanical properties of metal-roll production of OJSC Magnitogorsk Iron and Steel Works (MMK) in the storage and processing of consumers. For experimental studies were selected following assortment: galvanized rolled steel grades A341-A5, HX180BD, HX220YD, 006 / IFGR and cold-rolled steel grades and HC220Y 006 / IFCR production of rolling mill № 11 OJSC MMK. In laboratory conditions were simulated to ensure that the flow of natural and artificial heat, strain and thermal-aging. To determine the change in mechanical properties as a result of aging tests were performed on tensile investigated steel. The test results have been constructed according to clearly demonstrate the change in mechanical properties, and thus the inclination of the test of rolled metal to aging. It was found that the warranty period for the mechanical properties of high-strength steel grades HX220YD, HC220Y, 006 / IFCR and 006 / IFGR is 6 months. As for the rental of steel grades A341-A5 and HX180BD, hardening during the subsequent drying of the paint, the shelf life of such products must not exceed 3 months. After this period the metal begins to rapidly age and its technological and operating properties deteriorate significantly.