Corrosion testing of welds

[Harz]

I would appreciate very much if someone could offer me help in the following issues. All comments and suggestions are welcome. We develop a new class of high manganese steel (C < 0.4, Si = 0.6, 13 < Mn < 20, 3 < A < 8 and 3 < Cr < 8) and we have to investigate corrosion resistance of these steels. We have tested their corrosion resistance using immersion tests in 3.5 mass % NaCl solutions. Now we have to test the corrosion resistance of welded sheets of these steels (thickness 2 mm). Does someone have any idea how I could do that? I have read something about G48 standard, but if I have understood right, this standard is applicable only for crevice and pitting corrosion resistance testing of stainless steels welds. Or maybe I can use this method in my case, too? Is there some other standard for the corrosion testing of welds? Many thanks.

 

[EdStainless]

I would suggest that find someone skilled in the use of electrochemical testing.
This testing provides valuable feedback:
1. you control the area exposed (weld, base metal, different surface treatment) and it is a small (1cmsq) area.
2. you test in a fairly mild environment, one that at room temp will not lead to corrosion. This allows you to test for a wide range of corrosion resistance.
3. the results are quantifiable. You get numeric values that can be compared directly.

This is much superior to simple immersion testing.
Remember that you should also be testing samples of the currently used alloys also for comparison.

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Plymouth Tube

 

[cloa]

Just a little question what is A in the composition? And what is the potential applications?
Is it like

http://www.keytometals.com/Articles/Art69.htm

where its marine and cryogenic.

 

[Harz]

@EdStainless

Electrochemical corrosion tests of 50 samples of steel alloys with high Mn content prepared in a laboratory have been done. Since these types of steel alloys are prone to crevice corrosion, we have not managed to avoid the crevice corrosion during the measurement. Even more, the samples were highly inhomogeneous and immediately after immersing them into solution, before the measurement started, local and crevice corrosion took place. It led to the results with very low reproducibility. It was the reason that we have decided to start immersion tests. In the presence Cl- ions, these steel alloys have very low corrosion resistance, and consequently during an immersion test in 3.5% mass NaCl a high corrosion rate was found. A few selected samples with lowest corrosion rates were welded. At the moment, we would like to investigate the corrosion rate of these welded samples.

@cloa

Sorry! That's "Al".
It is not the same as Hadfield's steel. They have higher content of Al, Mn, and Cr, lower content of C, and Ni is not present.

 

[Harz]

@cloa

Automotive industry.