ASM Online Member Community

  • 1.  Challenge controlling base material

    Posted 03-07-2022 13:56

    Any advice?

    One challenges for me at work can be to understand and give guidance on how to control the base materials we use in production, through the different forming and heat treating operations we do, so as to obtain repeatable properties in the final products.

    Very similar (on paper/certificates) base materials may behave differently in our forming and heat treating operations. Finding the root-cause can be tricky, especially if you are not there collecting first hand information.

    Would love to hear your comments.

     



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    Niclas Bornegard
    Senior Innovation Enginner
    Swep International Ab
    Landskrona
    46709185572
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    Data Ecosystem - Global Materials Platform


  • 2.  RE: Challenge controlling base material

    Posted 03-08-2022 07:30
    Niclas,

    Factors for material consistency, and approaches for controlling the same, can vary based on material type (e.g. aluminum, steel, titanium, etc.) - are you able to say what types of materials you're working with?

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    Colin Fletcher, PE, CWI
    Sr. Metallurgist
    Xerox R&D / 3D Printing
    Cary NC
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    Data Ecosystem - Global Materials Platform


  • 3.  RE: Challenge controlling base material

    Posted 03-08-2022 09:23

    Hi Collin,

     

    Thanks for joining the thread.

     

    "Any advice?",  was perhaps the wrong formulation for a heading in this conversation, and a very big topic. Sorry for that.  The intension was more to formulate a discussion topic for "a room full of materials professionals".

    More appropriate would maybe have been: "is this a familiar challenge at work when you have forming and heat treating operations within your production?"

    We mainly use AISI 316 and 316L as base materials in our production of brazed plate heat exchangers. We do specify mechanical and chemical properties of the incoming materials.

    Depending on "what side of the table" you are sitting you may argue that the specifications are either too wide or too narrow. My experience is that wide specifications generally puts more pressure on production (operator competence, process control, maintenance etc.) while narrow specifications give purchasing departments head aces. The correct balance here I find is "tricky". Familiar "challenge" at work?

     

    BR

    Niclas

     




    Data Ecosystem - Global Materials Platform


  • 4.  RE: Challenge controlling base material

    Posted 03-08-2022 11:25
    Edited by Colin Fletcher 03-08-2022 11:25
    It's certainly a familiar challenge, and control of 300 series stainless material for forming was one of the most troublesome ones I've seen - I can give a quick example.

    Quick background is some common grades, like 302 and 304, were being used to form aircraft parts. With a fixed process, lot to lot variation would result in a variety of surface condition and texture issues. More specifically, conditions such as orange peel, Luders lines, etc. which were not acceptable on a finished part. 

    After a few attempts at making the process itself more robust (with very limited success), it was theorized that the primary cause was inconsistency in yield strength of the incoming material. Ranges in strength between the standard conditions (e.g. 1/4 hard, 1/2 hard, etc.) are fairly large in industry specifications, and material would bounce around those ranges quite a bit. Naturally, the next step was to impose additional controls on the incoming material to attempt to resolve the issue. An internal specification was created which essentially "hand picked" tighter ranges of strength from within the range provided by the industry specification.

    I did not personally work this issue, but regularly heard about it from another metallurgist who was involved. My recollection was that more closely controlled yield strength resolved most, but not all, of the problems. There were obvious impacts to cost and availability of the raw material, but I suppose it was preferred to the uncertainty of losing large portions of a batch of parts.

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    Colin Fletcher, PE, CWI
    Sr. Metallurgist
    Xerox R&D / 3D Printing
    Cary NC
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    Data Ecosystem - Global Materials Platform


  • 5.  RE: Challenge controlling base material

    W Michigan Chapter Adm
    Posted 03-14-2022 13:35
    Niclas,

    Challenges like you are seeing I feel are very common in all production. And I think the biggest issue to be overcome is an unfamiliarity with the materials, the standards, and the methods of determining the measured results. 

    I have the advantage of working with a team that tries to connect our facilities with our Customers regarding what they need. So I get to see both the Customer side and the Vendor side of these problems. In a lot of cases, the direct Customer, or the final customer, has no understanding of what they are trying to obtain. They see values for strength, hardness, or formability on different products and just assume they can pick and choose without having to deal with tradeoffs. So they overspecify a material and then are disappointed. On the other hand, there are a lot of customers who underspecify their materials, leaving such a wide window that final properties can vary significantly from batch to batch. We come across facilities that just order a "6063" alloy, thinking that is all they need to say, not understanding that 6063 has a big chemistry window which can result in wide variations in strength, formability, or anodizing response. And they get frustrated because they can't get consistent results.

    The solution (which for some reason many companies do NOT want to dabble in) is to get everyone together to discuss what the end goal is, and create a tight specification that everyone can live with. Producers (well, the good ones, at least) really want their customers to be successful, and want to make themselves invaluable in terms of assistance. And, likely, they are more familiar with the solutions to the end customer's problems than anyone in between.

    Back to the 6063 alloys, billet suppliers are ready and capable for casting to very tight "sub-windows" of chemistry with little to no upcharge, if it is common enough. By doing so, you can more tightly control properties, easing your own production problems and reducing scrap. So, it is in your best interest to reach out to them and see what they think is the best combination for your product. Maybe you don't care what the chemistry is, as long as it is 6063. So, the cast house can pick a convenient subset that matches their production and you can get improved consistency. And maybe you have a preference for a certain level of performance - very likely they can tune your chemistry for you while also improving consistency.

    And by working with the suppliers, they can prevent you (or you can prevent your customers) from over- or irrationally- specifying product. Such as by having a hardness tolerance so tight that standard uncertainty in testing means you can't legitimately achieve it.


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    David Betz
    Sr. Laboratory Engineer
    Hydro Aluminum Metals, USA
    dbetzasm@gmail.com
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    Data Ecosystem - Global Materials Platform


  • 6.  RE: Challenge controlling base material

    Posted 03-15-2022 03:38
    Well put David,

    Here we also see why "materials specialist" are so important on both sides of the table in the work of "continuous improvements".
    Both customer and supplier need to speak the same language and understand the counterparts challenges when exploring the way forward in finding the balance/compromise between price and performance. 
    BR
    Niclas

    ------------------------------
    Niclas Bornegard
    Senior Innovation Enginner
    Swep International Ab
    Landskrona
    46709185572
    ------------------------------

    Data Ecosystem - Global Materials Platform


  • 7.  RE: Challenge controlling base material

    Posted 03-15-2022 10:11
    One reason that people might be hesitant to develop tight tolerances with suppliers is evident right now due to supply shortages. It has become almost a daily event that I am told we can't get a certain grade of steel (typical alloy steels, nothing exotic) from the normal supplier and have to go elsewhere. We give the potential new supplier our internal specifications, and they tell me that they cannot meet some of the tolerances that are tighter than the industry standard and want to know if that is OK. Most of our internal specification were developed many years ago and it is difficult if not impossible to find evidence to answer the question. In some cases in which I actually find an answer, we had set our tolerances to the tightest that the original supplier could guarantee, for no specific reason other than the assumption that it would minimize variation. In any case, I either have to shut down production, or accept the material that does not meet our usual, but unexplained, restrictions. The latter is really the only option if I do not have a robust justification for the tighter tolerance.

    Of course, this can be helped by thoroughly documenting the development of the standard. In my specific case, that may have happened, but it was before computers were even part of the office environment, and the information is very often lost. Even if the information is filed away somewhere, finding the specific bit of information about the silicon tolerance on steel for one specific group of products is like looking for a needle in a haystack.

    Also consider changes in production methods. Some of these standards were defined well before EAF, continuous cast mini-mills were common. An aluminum killed steel might have been specified simply because that is the deoxidizer that the supplier used. Now, a continuous caster will tend to want to use silicon as the primary deoxidizer. Will it affect the product properties? Will it reduce tool life due to abrasive silicates? The answer to both is probably yes, but is the effect significant? That is much harder to say.

    I do feel the same way you do. It would be great to work closely with the producer of the material instead of buying commodity steel from service centers. When I worked for a steel mill, we worked closely with some pretty small customers to meet their needs (much smaller than my current employer). But, now I am seeing reasons that it can be difficult and even detrimental when things beyond our control change.

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    Ken Kirby
    Snap-on, Inc.
    Kenosha WI
    (262) 748-3836
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    Data Ecosystem - Global Materials Platform


  • 8.  RE: Challenge controlling base material

    Posted 03-15-2022 10:24
    It is definitely a common issue for me. I am often asked to explain why one material responded differently to an operation. Why is this material forming an unacceptable burr when we cut a blank? Why are chips not breaking during machining? Why is this material having quench crack issues?

    Of course, you have to question the operation itself. Was it done properly? Is the issue related to wear of dies or tooling? Many fine details are not documented and documentation is not always reliable. People automatically assume it is a material problem.

    Sometimes you can't solve the problem. Occasional quench cracks are particularly difficult. I have seen literature on the subject that literally says that some quench cracks cannot be explained, at least not without extraordinary efforts that are not justified for a one-time or occasional problem. Sometimes, all I can really do is verify that the raw material met specifications.

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    Ken Kirby
    Snap-on, Inc.
    Kenosha WI
    (262) 748-3836
    ------------------------------

    Data Ecosystem - Global Materials Platform


  • 9.  RE: Challenge controlling base material

    Pittsburgh Chpt Admin
    Posted 03-15-2022 11:31
    This has been a very nice discussion to read.  The frustrations expressed feel very familiar to me.

    I am on the producer side of the table and often get the sense that customers either don't know what they are asking for or why.  The situation Ken describes rings true where we might ask for some sort of deviation on a result and the customer is not equipped to evaluate whether a property or element falling this way or that will have a detrimental impact on the performance of their part. They might outright reject it out of an understandable conservatism.  I also identify with the situation David describes, where as the producer I just want the customer to tell me "what they really need", and let me sweat the details of how we get there.

    A disclaimer to the above is that I have sympathy for engineering controls.  Over-specifying seems like a reasonable approach to not invite unwanted variation into our lives, if a supplier agrees to the restrictions.

    What does everyone think the solution to this problem is?  How can we document the intentions of an engineer or group of engineers that author a specification so that future users of that spec can make educated decisions about altering it?  Should some sort of engineering justification document accompany every specification, at least internally?  There are also matters of intellectual property to consider, where suppliers might not want to divulge their methods for meeting a tight specification to protect their corner of the market, which can put end-users into a bind if they need to search for alternative material sources.

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    Stephen Rooney
    R&D Metallurgist
    Ellwood Materials Technologies
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    Data Ecosystem - Global Materials Platform


  • 10.  RE: Challenge controlling base material

    Posted 03-15-2022 14:23

    Hi Stephen,

    I agree, I too enjoy this discussion.

    I wish one could forget about obstacles such as NDA's between suppliers and customers, proof of the cost benefits (for implementation and management), etc.

    The dream, I guess for most material specialists on the floor, is the "big data", driven aid for "continuous improvements". Also the tool for facilitating " fact based" supplier-customer relations and specifications.

    It requires direct (on-line) input and access of the X's, e.g.:

    material properties of incoming goods from sub suppliers.

    internal process parameters.

    As well as the Y's:

    Internal results from inspections and validations, etc.

    Unfortunately, and as you pointed out, the matter of intellectual property is probably the biggest obstacle.

     

    BR

    Niclas

     

     

     

     

     




    Data Ecosystem - Global Materials Platform