The production of Advanced High-Strength Steels (AHSS) is crucial to modern automotive manufacturing, offering manufacturers the ability to produce safer and more fuel-efficient vehicles. AHSS combines exceptional strength with reduced weight, making it a prime material for improving vehicle performance and meeting regulatory standards. However, the process of producing AHSS poses significant challenges in maintaining consistent mechanical properties across the entire steel strip. Variations in tensile strength (Rm) and yield strength (Rp0.2) can lead to material defects, requiring costly rework and testing procedures.
Traditionally, steel production relied heavily on destructive testing to measure these mechanical properties, but this approach is both time-consuming and expensive. Moreover, destructive testing only provides data at specific points, making it difficult to identify issues throughout the entire production process.
The EMG Impulse Magnetic Process Online Controller (EMG IMPOC) system offers a non-destructive, online solution for measuring material properties such as tensile strength and yield strength throughout the production process. EMG IMPOC, designed specifically for demanding applications like AHSS production, enables manufacturers to optimise their production lines and ensure consistent quality.
Application in AHSS Production
To enable steelmakers to meet the stringent standards of the automotive industry, EMG IMPOC provides continuous, non-destructive measurements of these critical parameters, which can be used to monitor and adjust production online. Using an inductive method to measure the magnetic residual field strength of the steel strip, the system provides accurate data on tensile strength and yield strength, which typically range from 800 MPa to 1500 MPa for Rm and the corresponding Rp0.2 values for AHSS grades.
EMG IMPOC is specifically adapted for high-speed production environments, capable of operating at line speeds up to 900 meters per minute and handling material thicknesses between 0.15 mm and 3 mm. EMGs product portfolio also includes a special version, EMG Power IMPOC, which is designed for a higher thickness range of up to 6 mm.
This online data allows operators to identify deviations in material properties early in the production process, reducing the need for excessive destructive testing and minimising the risk of producing faulty material. As a result, manufacturers can optimise their processes more effectively, ensuring that AHSS coils meet the desired mechanical properties across the entire length of the strip.
Technical Highlights
EMG IMPOC operates on the principle of magnetic induction, which leverages the established relationship between the magnetic and mechanical properties of ferromagnetic materials. The system periodically magnetises the steel strip using a pulsed magnetic field, and the residual magnetic field gradient (remanence gradient) is measured by a highly sensitive magnetic field sensor. These magnetic measurements are then correlated with mechanical properties such as tensile strength and yield strength through regression models tailored for different steel grades.
In the context of AHSS, EMG IMPOC is especially valuable because it can deliver accurate online tensile strength and yield strength measurements. For example, AHSS grades like Dual Phase steels with ferritic-martensitic microstructure are well within the system’s measurement range, making it ideal for high-performance automotive applications. Moreover, the system is designed to identify minor deviations in the material properties of AHSS grades, which can have significant consequences on the production performance.
Benefits in AHSS Production
The integration of EMG IMPOC into AHSS production lines assures several critical benefits:
- Reduction in Destructive Testing
By continuously measuring tensile strength and yield strength EMG IMPOC reduces the need for frequent destructive tests. Typically, destructive testing is performed at the beginning and end of each coil. However, with EMG IMPOC, manufacturers can rely on online data to monitor material properties throughout the entire production process. This reduces the number of destructive tests by up to 50 %, saving both time and resources while maintaining quality standards.
- Improved Process Control
EMG IMPOC provides continuous data on the mechanical properties of the steel, allowing operators to make immediate adjustments to the production process. This online feedback is particularly important in AHSS production, where maintaining consistent material strength properties across the entire coil is essential. EMG IMPOC ensures that any variations, even if they are small, are detected and corrected promptly.
- Reduced Scrap and Rework
By identifying deviations in material properties early in the production process, EMG IMPOC minimises the risk of producing defective materials. This leads to a reduction in scrap and rework, critical factors in AHSS production due to the complex behaviour of these steels.
- Faster Coil Release
With EMG IMPOC, manufacturers can release coils faster by having immediate access to online data on Rm and Rp0.2. This eliminates the waiting time associated with traditional destructive testing, where results are often delayed by hours or even days. Faster coil release helps manufacturers improve throughput.
- Enhanced Quality Assurance
EMG IMPOC’s ability to provide online data on material properties also enhances long-term quality assurance. The system stores production data for up to three years, allowing manufacturers to track trends and identify correlations between production parameters and material properties. This historical data is invaluable for continuous improvement efforts and ensures that AHSS producers can consistently meet customer demands for high-quality materials.
Conclusion
The production of Advanced High-Strength Steels (AHSS) requires precision and consistency in material properties to meet the rigorous demands of the automotive industry. EMG IMPOC offers an innovative solution to this challenge, providing online, non-destructive tensile and yield strength measurements throughout the production process. With the ability to measure tensile strength from 800 MPa to 1500 MPa and corresponding yield strength values, EMG IMPOC is ideally suited to the high-performance requirements of AHSS production.
In an industry where precision and quality are paramount, EMG IMPOC provides the online insights needed to maintain high standards and optimise production processes, ensuring that manufacturers stay competitive in today’s challenging market.