Page 26 - MetalForming May 2015

Understanding the New, Stronger
Automotive Steels
No manufactured product better illustrates the contribution of material science to society than the current generation of automobiles, featuring improved performance in nearly every measurable category—handling, fuel economy, safety, etc.—due in large part to a slew of new steels. Equally impressive has been the technology developed to form these new alloys.
BY STUART KEELER AND PETE ULINTZ
Enthusiasts attending the latest round of car shows got a good dose of the impact being made by the new steels making marks on the industry. Numerous new models have seen significant additions of higher-strength steels, allowing carmakers to make impressive boasts about not only improved fuel economy, but also about improved performance. Automobile reviewers are quick to point to enhancements such as greater torsional rigidity, slashed braking times and improved responsiveness, as well as increased safety ratings, due in great part to the use of high- er-strength steels.
During the 1950s the standard steel of the day for most stampings in many industries was aluminum-killed draw- quality (AKDQ), with a yield-strength range of 20 to 40 ksi. The early 1960s had metallurgists working on high-strength low- alloy (HSLA) grades. They used smaller grain sizes, replaced iron atoms with atoms from other metals, stuffed carbon atoms between the iron atoms and made other modifications, resulting in steels with a yield-strength range of 35 to 80 ksi.
Stuart Keeler and Pete Ulintz author monthly columns in Met- alForming magazine and conduct seminars for the Precision Metalforming Association. Ulintz is advanced product engi- neering manager for Anchor Mfg. Group, Cleveland, OH; pete.ulintz@toolingbydesign.com. Keeler is president of Keel- er Technologies LLC, Grosse Ile, MI; keeltech@comcast.net
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MetalForming/May 2015
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