Page 24 - MetalForming July 2016

Straightening AHSS–
The Science Behind the Solutions
Stamping advanced high-strength steels can double the force and torque required of feed-line straighteners designed to feed mild steels. Often, custom straightener solutions are required to fit the application. New software utilities
can provide proof of concept before investing in new equipment.
In many cases, just replacing the top half of the straightener is all that’s needed to equip an existing coil-feed line to reliably feed AHSS. This includes, as illustrated here, a new head with the structural design and component content able to deliver the force needed for the application. Changing out components in the straightener involves, typically, use of smaller-diameter straightening rolls than those typically specified for shaping mild steels, and use of tighter center distances. The gearing also typically is upgraded.
BY BRAD F. KUVIN, EDITOR
Metalformers must be confident that the machines they’re buy- ing will stand up to the mate- rials they’re tasked with stamping today, and in the future. That’s the message coming loud and clear from suppliers of pressroom equipment in light of the onslaught of challenging metal alloys making their way into metalforming plants. Of primary concern are the numerous advanced high-strength steels (AHSS) that for several years have been mainstays in Tier One and OEM stamping facilities. Now these materials are making their way into many Tier Two and Tier Three stamping plants.
Compared to earlier times, when metalformers dealt primarily with steels in the yield-strength range peaking at around 50,000 psi, working with steels in the 100,000-psi or greater range requires an entirely new and unique set of equipment. And, the first step in the AHSS-forming process is perhaps the most challenging: straightening. To gain an understanding of the severity of this specific challenge, and for an update on how technology is evolving to sup- port the stamping community, we spoke with representatives from Coe Press Equipment Corp., Sterling Heights, MI.
“The most challenging step in the process of delivering AHSS sheet to the press is straightening,” says Coe
22 MetalForming/July 2016
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