> The standard way to test material's resistance to molten salt is to put a coupon in a crucible full of salt for a few hundred hours.
Q: What is a coupon in this context?
Q: What is a coupon in this context?
It is also a term for strips of metal that you mount in a corrosive environment as a way to monitor corrosion of other susceptible components. So if you were worried about your bronze bushings, you would buy some matching bronze coupons, put them in an area of similar flow, and measure their thickness periodically.
https://www.alspi.com/coupons.htm https://en.wikipedia.org/wiki/Fatigue_testing#Coupon_tests
>strips of metal
I mean in essence you just have to look at the word. Coupon is from French couper, which means to cut. So it's a cut-out. It has the same meaning when you look at extreme couponing and metal testing.
A weld coupon, for example, is a piece of test material of the same thickness and weld preparation as the main part being welded but is not integral to the part itself. That coupon is then sawed off and submitted for destructive tests like impact testing (to determine minimum operating temperature), tensile strength testing (specimen is pulled apart to find how strong and stretchy it is), and crystallographic etching (looking at the crystal structure of the metal to see if it has defects).
It is usually an artifact of materials like metal which are hard to cut, and can’t efficiently just be cut as needed during a task, but are prepared and pre-cut into small pieces you can grab easily. Each of those pieces is called a coupon.
I used to store mine in a Chinese takeout container box.
They would provide the school with bins of scrap from their manufacturing free of charge. Those were our practice coupons in class. We had to be careful to return the welded scraps back to the proper bin so the manufacturer could recycle them.
Our class was just a very small part of their recycling flow. It was a great relationship, we needed practice materials, and they hired welders.