IRMCO Advanced Lubricant Technology For High-Strength Steel

EVANSTON, Ill.--June 25, 2004--Evanston, IL based, IRMCO(R) has developed a high performance metal forming film that will provide automotive stamping suppliers much need relief as they are faced with the difficult task of getting high-strength steel (HSS) to form parts with tooling designed for mild steel. With structural metal stamping suppliers use of HSS increasing by 80 percent for the 2005 model this comes at a critical time. IRMCO's technology reacts with the increase frictional heat of HSS to provide a performance film that increase metal flow and stretch, thus reducing breakout scrap and rejects.

Controlling HSS Scrap Rates

The same attributes that give HSS its strength also can cause part reject rates to rise because of splits and poor uniformity if changes to improve metal flow and reduce friction aren't implemented. The material's high kilopounds per square inch (KSI) (a measure of yield strength), increased springback, and tendency to work-harden and run at elevated forming temperature create a host of tooling challenges. According to an American Iron and Steel Institute/Department of Energy study, HSS has up to half the elongation percentage as mild steel. In addition to reduced n value, making HSS significantly more difficult to draw than conventional cold-rolled grades. The reports also states that the forming lubricant quality influences drawability.

Test Case: Tier 1 Supplier Controls Frictional Heat

During a recent production test at a Tier 1 automotive supplier, IRMCO's high solids polymer (HSP) lubricants proved to provide consistent tool protection and friction control on a suspension part made from 82-KSI ultra high-strength steel (UHSS). During the evaluation, temperature, strokes per minute, and part quality were measured. The temperature averaged 240 degrees F. The same part made from 50-KSI material averaged 150 degrees F. Part uniformity and material thinning were measured with circle grid analysis. The test resulted in consistent tool protection and acceptable part uniformity. The lubricant was able to provide the necessary tool protection even at very high temperatures.

EP (Extreme-Pressure) Versus ET (Extreme-Temperature) Lubricants

Historically, EP (extreme-pressure) lubricants have been considered the best approach to achieving high-performance tool protection on the most demanding deep-drawn or heavy-gauge formed parts. Sulfur and chlorinated EP additives blended with straight oil have a long history of improving tool life success. With the introduction of new-generation metals such as HSS, and stringent environmental and disposal requirements, EP oil's value has diminished. Under the high heat required to form HSS, EP oils lose their performance. They can't provide the physical tool-protecting barrier required for ET (extreme-temperature) applications. ET versions of IRMCO's HSP lubricants do provide the necessary protection. As metal deformation in the stamping press raises tool and metal temperature, EP oils become thinner, and in some cases flash or burn. The average HSP lubricant has a thin viscosity when applied; however, as the temperature rises, the viscosity becomes thicker and more tenacious. In fact, ET fluids are heat-seeking and will attach to hot metal, creating a friction-reducing film barrier. This protective barrier allows the tool to stretch and form metal without splitting or metal pickup during the most demanding operations, thus controlling friction and metal flow.

IRMCO, is an advanced lubricant technology firm in Evanston, Ill., specializing in metal strain, friction analysis, and process optimization, For additional information on IRMCO's ET HSP technology for High Strength Steel, contact IRMCO at: 847-864-0255, ext. 3019, email: brad@irmco.com, or visit IRMCO on the web at: www.irmco.com