Glenn Posted August 15, 2008 Share Posted August 15, 2008 I have received a question that I will put to the forum. Is there a quick or easy way to tell the composition of metals in the field?Is there a way to distinguish Ferritic Stainless Steel from highly polished plain steel. How can I get more information about metals being recycled or at the junk yard, something more than "shiny rods of metal"? Quote Link to comment Share on other sites More sharing options...
BeaverDamForge Posted August 15, 2008 Share Posted August 15, 2008 If you can heat it, shouldn't you be able to tell the difference by the scale (or lack of) formed? Good Luck! Quote Link to comment Share on other sites More sharing options...
Quenchcrack Posted August 15, 2008 Share Posted August 15, 2008 There are kits with various chemicals that can be applied to metals and depending on the color of the spot formed when a drop of certain chemical combinations are put on the steel, it can be generally identified. These can be purchased from metallurgical supply companies. Bring lots of $$$. Otherwise, bring a package of chlorox handiwipes to the junk yard with you. Polished carbon steel should show darkening and/or rust fairly quickly where SS would not. Quote Link to comment Share on other sites More sharing options...
fat pete Posted August 15, 2008 Share Posted August 15, 2008 An experienced friend stopped by the other day and I had some of the same questions...his reply was to spark it...he took it to the wheel and ever so lightly ground some off...but it took him a couple of minutes to examine the sparks...gave me another view of spark testing , the thought that it takes a litle while to observe the spark pattern and colors...also some SS is non magnetic some has some magnetism... Quote Link to comment Share on other sites More sharing options...
Quenchcrack Posted August 15, 2008 Share Posted August 15, 2008 The art of spark testing required considerable training and relied on comparing the spark pattern from a KNOWN alloy with the unknown alloy. The composition of the grinding rock, the grit, the pressure, etc, must all be carefully controlled and this required experience and training. I know of nobody in the US steel industry that still uses this method since portable spectrometers can be put in the bed of a truck and taken to the scrap heap. An exact analysis is printed out in seconds. There is a BP on spark testing here somewhere but at some point, it lost all of its spark drawings and is now fairly useless.BP0020 Spark Testing click on thumbnails to enlarge images. Quote Link to comment Share on other sites More sharing options...
teejay Posted August 16, 2008 Share Posted August 16, 2008 Take a magnet and a file with you carbon steel is magnetic, 300 series stainless is not ,400 series is slightly magnetic,not as much as carbon, should be able to tell cast iron with the file.Now some alloy stainless is as magnetic as carbon such as 17-4,18-8 stainless that you just have to spark test or forge. Quote Link to comment Share on other sites More sharing options...
Quenchcrack Posted August 16, 2008 Share Posted August 16, 2008 440C is highly magnetic. It is a martensitic stainless used for cutlery. It is the regretable disarray we find our US numbering system in today. Austenitic stainless can also be slightly magnetic if it has been heated or welded upon. This tends to form islands of ferrite in the austenitic structure and the ferrite is magnetic. All very confusing even to professionals. Quote Link to comment Share on other sites More sharing options...
Quenchcrack Posted August 16, 2008 Share Posted August 16, 2008 Glenn, thanks for finding the BP on spark testing. In the original document I sent you, there were a series of drawings of the shape of the spark for each element. They all have unique stars, arrows, clusters, etc. It is necessary to have the details of each element in order to pick out the specific elements in an alloy. These came from a book, long out of print, from the 40's I believe. I have photo copies around here somewhere but if I cannot find it, we may have to do some internet searches to complete the BP. Quote Link to comment Share on other sites More sharing options...
Quenchcrack Posted August 16, 2008 Share Posted August 16, 2008 Sometimes I am amazed at my good filing....... or good luck. I found the original paper copy of the BP INCLUDING the drawings of the spark detail for each element. The bad news is my HP scanner no longer works now that I upgraded to the new and improved version of Internet Exploder. I will scan it when I return to work in a week or two and send it to you. And yes, I downloaded the patch and it still doesn't work.....sort of like Bill Gates. Quote Link to comment Share on other sites More sharing options...
Glenn Posted August 16, 2008 Author Share Posted August 16, 2008 Quench, send them to me when you get a chance and I will add them to the Blueprint. The beauty of the blueprint system is that they can be corrected or additional material added when it becomes available. Quote Link to comment Share on other sites More sharing options...
John B Posted August 16, 2008 Share Posted August 16, 2008 Is this link of any use?Spark Quote Link to comment Share on other sites More sharing options...
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