After reviewing the results of a battery of paint performance and welding tests conducted on EPS samples, the two automotive OEMs approved the use EPS-processed steel as a replacement of acid pickled for end use product application. The tests were sponsored by a major steel service center operating an EPS production line. That service center is a long-time supplier of flat rolled steel to automotive OEMs and Tier 1 suppliers. They were conducted over the course of 2013.
 
All paint pretreatment, appearance and corrosion tests were performed by the accredited testing laboratory ACT of Hillsdale, Mich. The welding research and testing firm Applied Engineering and Integration, Inc. (AET Integration) performed the resistance spot welding tests and analyses. All tests were performed in accordance with the relevant GM and Chrysler standards. For the paint appearance and corrosion tests, all samples were cleaned, pre-treated and painted in accordance with automotive exposed panel standards.
 
The EPS process is an environmentally friendly replacement for acid pickling of hot rolled steel strip developed by The Material Works, Ltd. (TMW) of Red Bud, Ill., USA. This patented process removes the layer of oxide (mill scale) from the surface of hot rolled steel, imparting a very clean, uniform surface. Unlike acid pickling, the EPS process uses no hazardous substances to accomplish its 'pickling' — just ordinary water and fine steel grit — which are recirculated for continuous use. The process also leaves the steel inherently rust resistant, so it does not require the oil film that is applied to acid pickled steel to prevent rusting. See www.epsprocess.com for further details.