There is interest in the sheet metal industry on how to adopt Industry 4.0 into their legacy forming practices to significantly improve productivity and product quality. Figure 1 illustrates four important variables influencing part quality: material properties, die friction response, elastic deflection of the tool, and press dynamic characteristics. These variables are usually difficult to measure or track during the production runs. When these variables significantly influence the part quality and the scrap rate increases, the operators manually adjust the forming press parameters (speed and pressure), lubricant amount, and tooling setup. However, these manual adjustments are not always possible or effective and can be costly for the increased part complexity.
Figure 1: Important variables influencing the stamping quality.H-35
The ultimate vision for Industry 4.0 in sheet metal forming is an autonomous forming process with maximum process efficiency and minimum scrap rate. This is very similar to the full self-driving (FSD) vision of the electric vehicle today. This will be valuable for the automotive industry that has to process large production volumes with various steel grades.
For example, normal variations of the incoming material properties for Advanced High-Strength Steel (AHSS) may have a significant effect on part quality associated with necking, wrinkling, and cracking, which in turn drastically increases the production cost. This variation of the incoming material properties increases uncertainty in sheet metal forming by making consistent quality more challenging to achieve, thereby increasing the overall manufacturing cost. A nondestructive evaluation (NDE) can be a useful tool to measure incoming material properties.
There are several types of NDE sensors. Most of the sensors need further development or are not suitable for production applications. However, some of the NDE sensors, such as the eddy current tools, laser triangulation sensors equipment, and equipment developed by Fraunhofer IZFP called 3MA (micromagnetic, multiparametric microstructure, and stress analysis), have already been applied to a few limited production applications. These sensors can be used to provide data during production to select the optimal parameters. They also can be used to obtain material properties for finite element model (FEM) analysis. Studies in deep drawing of a kitchen sink production used a laser triangulation sensor to measure the sheet thickness and an eddy-current sensor to measure the yield strength, tensile strength, uniform elongation, elongation to break, and grain size of the incoming material. The material data is used as an input for simulations to generate the metamodels to determine the process window, and it is used as an input for the feed-forward control during the process.K-27
Figure 2 shows how NDE tools are used for feed-forward controls and cameras for feedback control to determine the optimum press setting on sink forming production.
Figure 2: Process control for sheet metal forming of kitchen sink production.H-36
Another study proposed the use of Fraunhofer’s 3MA equipment to determine the mechanical properties of incoming blanks for a sheet forming process. The 3MA sensor correlates the magnetic properties of the material with the mechanical properties and calibrates the system with the procedure outlined in Figure 3. The study showed a good correlation between the measurements from the sensor and the tensile testing results; however, the sensor should be calibrated for each material. Also, the study proposed to use a machine-learning algorithm instead of a feed-forward control to predict the most effective parameters during the drawing process.K-28
Figure 3: Calibration procedure for 3MA sensors.K-28
Technologies associated with Industry 4.0 have a natural fit with AHSS. The advanced slide motion capabilities of servo presses combined with active binder force control can be paired with stamping tonnage and edge location measurements from every hit to create closed-loop feedback control. With press hardening steels (PHS), vision sensors and thermal cameras can be used for controlling the press machine and transfer system.
Have a look at the Dr. Kim’s detailed article on Industry 4.0 for more examples of NDE sensors, as well as information on applying Industry 4.0 to forming process controls.
WorldAutoSteel will consider appropriate articles from expert sources for publication on our AHSS Insights blog. In order to be considered, you must meet the requirements set forth below. Please keep in mind, however, that we do not pay for, or charge for, posting guest blogs. But we are more than willing to consider articles that are relevant to educating on best practices and new processes in the forming and joining of Advanced High-Strength Steels (AHSS) in vehicle applications.
If you still have questions about being a Guest Blogger for WorldAutoSteel after reading this page, you may contact the AHSS Guidelines Editor, Kate Hickey.
Please keep in mind the following fundamentals before you start writing your blog.
- Your submission must contain references to Advanced High-Strength Steel (AHSS) in vehicle applications. Note that the name of our blog is AHSS Insights, therefore, readers will be expecting to expand their AHSS knowledge base.
- Your submission must be geared towards a technical audience, with appropriate data references. Our audiences include automotive engineers that specialize in design, materials, manufacturing and the environment. We generally do not accept thought-starter type guest blogs.
- Your submission must not be a marketing piece for your organization, proprietary products or services, nor should it contain marketing messages and solicitations. Our readers are smart people. They will appreciate and gain much more insight into your company by simply demonstrating your expertise and showing your products’ purpose in AHSS use, than they would in a sales pitch.
- It should contain information pertinent to our audiences on an aspect of AHSS, such as AHSS characteristics, use, metallurgy, forming or joining. It also may address vehicle or steel industry life cycle assessment or other environmental issues related to automotive and AHSS use.
- Your submission must include graphic references. You may decide what kind of graphics you would like to add such as charts, videos, infographics, etc. We welcome videos as long as they do not include a sales pitch. Graphics need to be submitted as PNG or SVG files, and videos must be a standard format, such as MP4 or WMV.
Please meet the following submission requirements before you submit your entry for consideration.
- Submissions should be around 1,000 words, and include graphics.
- Please include a title.
- Graphics should be provided as separate 72 dpi (PNG or SVG) files, if possible, and sourced appropriately, especially if you do not specifically own the rights. Videos should be 720p resolution.
- Please clearly provide any reference sources in the following format: Author, full title of the work, year published, and if available and it will add to the blog’s content value, provide an internet link to the work.
- Please notify us with your intention to submit with an brief abstract of the information you will cover. This will help us determine if it is a good fit and enable us to potentially provide provisional approval.
- Your first draft must be submitted a minimum of 30 business days prior to any agreed upon publish date. This allows our team to have ample time for review, give you feedback and pursue any required further editing. It also provides time for translation to our Chinese blog edition.
- As your blog will be translated to the Chinese language and published on our channels in China, please do not use English jargon that will be difficult to translate.
We will notify you in advance as to when your entry is scheduled to publish. We strongly encourage you to use your social contact network to share the blog article. Your shares should include our blog hashtag, #AHSSblog.
Submitting Video and Animation Assets
We are always looking for video and animations to help support existing articles with visual information. If you think you have something that would enhance an article, please contact us at the email link above. You can send us a link to what you have, and we will review it. Note, the video must be owned by you in order to be considered and not contain any sales pitches. If we agree to use it, we’ll need to receive the original video file so that it can be uploaded directly to our site. You/your company will receive full citation as a the source of the video. Have a look at our Roll Forming page to see an example of how we have used a video received from Shape Corp.
We look forward to receiving your submission. It is our pleasure to collaborate on AHSS education with you. Thank you!