Analysis of Factors as Affecting Cold-forming Performance of TP439 Strip Steel

Tow TP439 strip steels with same thickness，different chemical compositions and made with different manufacturing processes are used to produce the products with the same size via the same cold-bending formation process. The key factors as affecting the cold-bending forming performance of the TP439 strip steel，i.e.，the chemical composition and the finish-rolling temperature are identified by means of testing and analyzing the metallographic structure，the residual stress（via the C Type Method），the tensile property and the hardness，etc. Comparatively Elements C and N in the chemical composition produces more obvious influences mainly on the hardness，the strength and the elongation of the strip steel， while the finish-rolling temperature mainly affects the grain size；and the low hardness，the low yield strength，the high elongation and the fine grain size of the strip steel are helpful for cold-bending formation of the strip steel. The result of the above mentioned analyses is worth using as the guide for controlling the performance of the strip steel for cold-bending formation purpose.