The Advanced High-Strength Steels Application Guidelines Version 4.1
Just as the world’s auto industry is doubling efforts to reinvent itself, so too is its primary materials supplier in the form of new global guidelines for advanced high-strength steels (AHSS). Much like the internal combustion engine itself, steel—still the essential structural and body material for the world’s carmakers—is reinventing itself to meet the daunting challenges faced by automakers worldwide.
WorldAutoSteel, the automotive group of the World Steel Association, released of the newest version of the Advanced High-Strength Steel Application Guidelines (AHSS Application Guidelines), bringing together the world’s experience and knowledge on the use of the latest sheet steel technology. The Advanced High-Strength Steel Applications Guidelines (AHSS Application Guidelines) Version 4.1 is available free for download today (click download link under Attached Files).
AHSS Application Guidelines Version 4.1 will assist global automotive manufacturers in the successful application of new, lighter steels; these steels achieve higher strength body structures, with lower weight, and result in fewer CO2 emissions compared to other body materials. Just as importantly, the AHSS products allow for improved safety performance, while meeting manufacturing cost limitations.
“The global steel industry is continually reinventing its products to develop materials that are lighter, safer, greener and cost effective,” said Edward Opbroek, Director, WorldAutoSteel. “Steel, and particularly, Advanced High-Strength Steel, is the only material that delivers improved environmental, safety and vehicle performance at little or no cost penalty to manufacture.”
AHSS application in automotive structures has increased since the steel industry’s UltraLight Steel Auto Body (ULSAB), UltraLight Steel Auto Closures (ULSAC) and ULSAB-AVC (Advanced Vehicle Concepts). These programmes have successfully demonstrated weight savings and performance improvements at no cost penalty over similar applications using conventional steels. AHSS is rapidly becoming the predominant material in typical body structures, reinforcing the need for these application guidelines.
Most striking in the updated Section 1 Metallurgy is the list of available AHSS grades. At the start of the ULSAB-AVC programme, only eight AHSS steels were in use among WorldAutoSteel member companies, which constitute the largest sheet steel producers in the world. Today, less than 10 years later, these members report twice the number of different AHSS grades that are being considered for automotive applications, including the Future Steel Vehicle, WorldAutoSteel’s latest programme. This dramatic growth of AHSS products is indicative of the rapid adoption by automakers of these new lightweight steels and their importance to vehicle engineering. Included in this update are additional details regarding Hot Formed steels.
Version 4.1 includes new sub-sections on Sheared Edge Stretching Limits, Lubrication, Tube Hydroforming, and Hot Forming, which have an important influence in sheet forming operations, but more so as steel strengths increase, such as with AHSS.
Version 4.1 also adds to the available data, which can be used to compare potential forming parameters, press loads, press energy requirements, and other parameters when switching among different steel types and grades.
Another important update in this version is a complete review and revision of the Joining technologies section. This revision includes added content on coating effects, shear tension strength of welds, fatigue of spot welds and updates to the sub-section on mechanical joining. These revisions continue to add to the breadth of information available in the world today on joining technologies for AHSS.
AHSS Application Guidelines Version 4.1 also features a Glossary of Terms that combines the previous version with that developed by the Automotive/Steel Partnership (A/SP), providing the most comprehensive reference currently available. Further, an Appendix adds case studies developed by the A/SP that give summaries and valuable insight into development of complex part shapes using AHSS.
Guidelines: Public, Free Availability
The AHSS Application Guidelines Version 4.1 is available for free download (see upper right of this page). It is also available through WorldAutoSteel member company steel representatives.
WorldAutoSteel member steel companies are making this valuable knowledge base available to OEMs, suppliers and others who can benefit. Member companies hope to provide a resource through it that will have significant impact on AHSS use in the industry, saving auto engineers time and expense incurred by learning through trial and error.
Interaction for Further Development
To further assist OEMs and their suppliers, WorldAutoSteel member companies continually seek to work with customers to apply Advanced High-Strength Steels to meet automotive application goals, whether that is in creating the right mix of AHSS properties for a specific application or helping with other design and manufacturing challenges. Interaction is encouraged as OEMs and suppliers work with this steel technology.
As well, WorldAutoSteel is committed to continuous improvement of the AHSS Application Guidelines to reflect the ever-increasing global body of AHSS vehicle applications knowledge. To this end, steel company feedback, as well as valuable feedback from OEMs and suppliers is actively sought, with the expectation to update and add to the current information over time.
About AHSS Guidelines
With increased use of Advanced High-Strength Steels comes the need for sharing of application guidelines and production experiences, especially in forming and joining. WorldAutoSteel member companies evaluated the need for a consolidation of descriptions, data, problem solutions, and explanations concerning AHSS and found AHSS steels are being produced and used in many stampings worldwide. While the necessary quantity of data is available on the subject, it is distributed in many forms in many different regions of the world. Most importantly, users of AHSS are looking to steel companies for additional data and guidance.
Consequently, member companies of the WorldAutoSteel undertook the challenge to compile a global knowledge base of AHSS data and experience. The goal was to create a user-friendly documentation of the data and experience of the WorldAutoSteel member companies, which would capture a worldwide body of information on AHSS applications.
Dr. Stuart Keeler serves as technical editor of the AHSS Application Guidelines. Dr. Keeler began his extensive sheet metal career when his research on sheet metal forming limits led to his development of the Forming Limit Diagram, now widely used to predict forming severity of sheet metal stampings. Dr. Keeler brings this vast experience to task in bringing together steel expertise to complete AHSS Application Guidelines updates.
WorldAutoSteel member companies’ work resulted in the AHSS Application Guidelines, containing more than 150 pages of information with over 200 figures and graphics. AHSS Application Guidelines documents valuable information primarily focused on automotive body-in-white applications of this steel.