Formed in 1987, the Auto/Steel Partnership is a consortium of Steel Market Development Institute’s Automotive Applications Council, FCA US LLC, Ford Motor Company and General Motors Company. The Partnership leverages the resources of the automotive and steel industries to pursue research, validation and education that have helped automakers enhance vehicle safety and fuel economy and improve design and manufacturing. Through the Auto/Steel Partnership, automakers and steel companies have worked to drive improvements from concept through realization in vehicles on the road today.
The Auto/Steel Partnership will deliver to the automotive industry future steel innovations and solutions that meet society’s needs for sustainable vehicles.
To achieve sustainable automotive solutions, Auto/Steel Partnership will appropriately leverage the:
Advanced High-Strength Steel (AHSS) Repairability is a continuation of two earlier phases of an Auto/Steel Partnership project which sought to develop repair and serviceability technologies for various grades of AHSS having tensile strengths greater than 780 MPa. This phase (Phase 3) of the project will develop automotive repair guidelines for AHSS grades having tensile strengths between 780 MPa and 1800 MPa. As with the two earlier phases of the project, the goal of this phase of the project is the continued expansion of existing automotive repair matrices.
AHSS Stamping investigates a wide array of studies supporting the accelerated application of innovative AHSS products to reduce vehicle weight and to improve structural performance. The approach is to divide the broad project spectrum of possibilities into three categories, including: evaluate the steels using baseline industry tools; address production challenges; and improve capabilities for analysis methods. This approach reinforces the focus on projects to support team goals. The team selects new and known control AHSS products to make real-world components. Extended carry-over work examines the properties of new AHSS products, their performance in critical edge cracking conditions and ways to locally modify properties to achieve forming success and assembly fit up (springback). Understanding of new AHSS properties and microstructures are uniquely important for their effects on springback modeling for designing optimized components and full-body structures. Projects to examine the new AHSS product microstructures expand understanding for meeting production challenges. Additional efforts are ongoing to apply new approaches and technologies to address expanded AHSS designs and applications. The AHSS stamping team works with other A/SP project teams to improve analysis capabilities. The AHSS stamping team and the non-linear strain path teams are contributing to a project on optical FLC determination using a new, innovative approach that benefits both teams.
Corrosion of AHSS in Chassis Applications was created as the current corrosion resistance method may present a roadblock to further implementation for lightweighting using AHSS in chassis component usage. In addition, current corrosion resistance requirements are being increased and closed sections, welds and larger heat affected zone must be addressed. The team develops procedures, materials and method processes to accomplish 15-year corrosion adequacy for lightweight chassis AHSS applications.
Delayed Cracking of AHSS determines or develops a qualification-level test to demonstrate the susceptibility of various AHSS and ultra high-strength steel (UHSS) microstructures (TS > 800 MPa) to exhibit delayed cracking. Although many delayed cracking test procedures are available, they are overly severe and can crack materials that have been applied successfully with no delayed cracking failures. The project selects a current test that has high potential and modifies it to be able to differentiate materials. The test is easy to run, could be used for new grade validation and can be modified to OEM material selection criteria. The test will be applicable to steel with or without additional manufacturing (plating, welding) or in-service (corrosion) inputs. The goal is to create a realistic method to evaluate relative performance of new AHSS and / or UHSS with respect to delayed cracking.
Fracture Prediction is developing and validating robust computer aided engineering (CAE) models for predicting fracture in AHSS / UHSS. Early CAE prediction of material fracture is critical to the OEMs and relies on the accurate simulation of material and part behavior under different loading and strain rate conditions. This, in turn, requires the use of accurate material models throughout the part loading history and a representative / validated material failure criterion. The three phase project will in the near term address immediate OEM needs by providing correlated / validated fracture CAE modeling techniques for use with AHSS / UHSS (including the determination of the critical material fracture properties, failure criteria, mesh size, etc.), conduct a parallel study to assess weld fracture behavior, and propose proper simulation methods to predict failure. The next mid-term phase will investigate the influence of different processing parameters (blanking, trimming, etc.) on material fracture and propose a set of recommended best practices. The third and final phase will study the influence of microstructure on fracture to enable the development of appropriate material processing windows that will ensure consistent and predictable behavior. The benefits of this project will be the continued use of newer grades of AHSS / UHSS to meet safety and crashworthiness performance targets while still achieving the desired mass reduction, a recommended approach to CAE simulation and prediction of fracture failure under crash loads, and the establishment of material / part design / part processing recommended practices to ensure robust performance under crash loads.
Gas Metal Arc Welding (GMAW) of AHSS was designed to develop and validate a GMAW approval process for AHSS for use by automakers and steel companies. The team evaluates the state of previous studies and efforts on this issue, including European and other international and U.S standards and methods. A common test methodology for GMAW of AHSS will be developed and considered by the team. Finally, if a methodology for testing effects of GMAW on new AHSS can be determined, it will be published as a national or international standard.
GMAW Fatigue Modeling is developing and validating CAE models for predicting weld performance in AHSS grades for automotive applications. Most automotive assembly durability issues are related to welds. Due to the increasing use of thinner gauge AHSS steels to meet automotive cost and mass targets, welds are expected to play an increasing role in the quality, reliability and durability performance of automotive structures. Therefore, accurate prediction of weld fatigue is very important and improved and more accurate CAE weld fatigue models are needed to facilitate the development, validation and implementation of automotive lightweight highly integrated AHSS structures. This project will develop robust CAE fatigue models to predict the performance of complex welded AHSS assemblies (e.g., cradles, cross-members and twist axles). The project will further enhance existing CAE weld models and expand their applicability to AHSS by modifying them with experimentally derived constitutive material property data and validating them with component-level testing. The two-year project will improve our understanding of physical welds and their effect on fatigue performance, provide enhanced weld design and weld management techniques (e.g., weld placement in the structural configuration), and provide AHSS CAE fatigue modeling techniques, which are more predictive of production weld performance.
Hemming of Thin Gauge AHSS goals include: deliver a set of computer-aided engineering tools to simulate the hemming of thin gauge AHSS closure panels; identify potential dimensional accuracy and stability issues that will be encountered when hemming thin gage AHSS closure panels; and deliver a suite of design and manufacturing toolkits to improve dimensional capabilities and robustness of hemmed thin gauge AHSS closure assemblies.
Improved Fatigue in Fusion-Welded Joints investigates opportunities to improve GMAW joint fatigue life of AHSS through development of optimized joint geometry guidelines and weld profiles. This team provides optimum material, joint design and process solutions, so that joints using AHSS in lightweight chassis components achieve validated results. The aim is to have the fatigue life of the joints equivalent to 80 percent of base metal.
Integrated Computational Materials Engineering of 3GAHSS is developing an integrated computational materials engineering (ICME) model for the development of third generation advanced high strength steel (3GAHSS). 3GAHSS, have been defined as those steels that have both exceptional ductility and strength, representing an ideal opportunity for automotive OEM’s to design and implement lightweight complex integrated steel structures to meet increasing fuel economy targets and emissions requirements. The goal of this project is to simultaneously develop 3GAHSS technology to support immediate weight reduction in passenger vehicles while also advancing ICME techniques to support a reduced development-to-deployment lead time in all lightweight materials systems. The objective of the project is to successfully demonstrate the applicability of an ICME approach for the development and deployment of 3GAHSS, which will integrate results from well-established computational and experimental methodologies to develop a suite of material constitutive models (deformation and failure), manufacturing process and performance simulation modules, as well as the computational environment linking them together for both performance prediction and material optimization. Upon conclusion in January, 2017, the four year, $8.6 million project will deliver a validated 3GAHSS ICME model and user guide, which includes a 3GAHSS material property database and technical cost model
Joining High Carbon Equivalent AHSS investigates the joining issues associated with higher-strength steels. As these newer materials are evaluated for formability and stamping feasibility, a commensurate assessment is required for joining these higher-strength steels. The project is working to establish process parameters and guidelines for spot welding AHSS and UHSS steels.
Non-Linear Strain Paths goals include developing a fundamental understanding of material behavior from manufacturing (stamping / hydroforming, bake-hardening) to performance (crashworthiness, strength, and dentability) by developing, implementing and validating reliable constitutive and failure models and delivering an integrated solution to vehicle engineering and manufacturing. Opportunities exist for weight reductions if a vehicle is engineered to take full advantage of sheet metal capabilities, especially AHSS that exhibit rapid hardening and complex deformation behavior. Vehicle engineering practices often rely on simplistic material models and ideal material mechanical properties that do not realistically take into account the impact of the strain history in stamping, paint baking cycles and the complexities of combined manufacturing and product performance simulation. In addition, fracture modeling during a crash event is almost non-existent in safety design, where expensive prototype testing is necessary to validate crashworthiness. The advanced material models developed in this project will be useful to manufacturing and product engineering, enabling more reliable determination of manufacturability and product performance to take better advantage of lightweighting opportunities through design optimization.
Steel Testing and Harmonization pursues the development of common qualification and test procedures for sheet steel. The primary goal of the project is to avoid future OEM testing divergence and associated costs. A secondary goal is to help streamline the evolving product development cycle. Efforts include development of standardized, local formability testing and reviewing all related automotive and steel qualification and testing procedures.
Stamping Tooling Optimization addresses the need to fully realize the benefits of AHSS, which depends upon the ability to aggressively form, trim and pierce these steels into challenging geometries needed for automotive applications. The tooling used to stamp AHSS is subject to a variety of forces resulting in different failure modes, such as edge chipping, excessive surface wear and galling or spalling of coatings. The selection of tool steels, heat treatment, surface treatment and coatings is dependent upon the nature of the operation, applied forces and expected failure mode. The goal of this project is to determine cost-effective and durable-die materials, surface treatments, and coatings and die designs for stamping AHSS by developing and implementing tests that simulate die tool environments and failure modes. This program expects to continue the success of prior programs, which have demonstrated technology transfer where project test results have been implemented by the automotive OEM.