Abstract: Three different chemical composition approaches of hot rolled high-strength low-alloy (HSLA) grade 80 (550 MPa) steels, Stelco trademarked STELMAXTM80, produced at Stelco’s Lake Erie Works (LEW), were studied to correlate composition with microstructure and edge stretchability. Each product showed a ferrite, pearlite microstructure with fine precipitates. Mechanical properties of each design were very similar, however, the hole expansion ratios ranged from 48% to 68%. Metallography, fractography and inclusion studies were conducted to determine the underlying factors that control edge stretchability during hole expansion testing. Some basic trends were detected which could be useful in designing new HSLA steel grades with enhanced edge stretchability.
Authors: David Overby, Chad Cathcart, Xingcai Yu, Tihe Zhou, Peter Badgley, and Chris Martin-Root
Keywords: High-strength low-alloy steel, Microstructure, Hole Expansion, Edge Stretchability