LOW CARBON BAKE-HARDENING STEEL SHEETS PRODUCED THROUGH BATCH ANNEALING ROUTE AND A PROCESS FOR ITS PRODUCTION.

摘要

ABSTRACT TITLE: LOW CARBON BAKE-HARDENING STEEL SHEETS PRODUCED THROUGH BATCH ANNEALING ROUTE AND A PROCESS FOR ITS PRODUCTION. The present invention relates to high strength rephosphorized Low Carbon Bake hardening steel sheet having excellent formability and surface finish, and a method for manufacturing the same through batch annealing route. The cold rolled batch annealed bake hardening steel sheet obtained by the process is intended mainly for outer panel material for automobile application where the strength of the drawn parts can be further increased by paint baking process. Importantly, the developed steel grade is a low cost low carbon steel with carbon wt% ranging from 0.01-0.02 wt% and micro alloying with B, having yield strength YS of not less than 220 MPa, before bake hardening, average r-value of higher than 1.6 and a Bake hardening (BH) value of not less than 35 MPa, favouring application in low tare weight dent resistant car body fabrication leading to improved fuel efficiency.