What Grades of Stainless Steel Resist Oxidation at What Temperatures?

October 30, 2013 | Sheet Metal Fabrication, Stainless Steel Baskets

 

Maryland metal
304 Stainless being cut for Marlin Steel

Manufacturing engineers looking for stainless steel products want to know what type of stainless resists corrosion at different temperatures.

Stainless steel is not technically unable to stain or rust. Under low oxygen or high salinity (saltwater), it’s susceptible to corrosion. Various grades of stainless react differently, based on their chemical composition – how much carbon, chromium or nickel they contain. The chromium in stainless steel forms a film that blocks oxygen from corroding the steel surface. The result is “passivation,” which means the material is passive, not so active, when confronted by substances like air and water.

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Temperature, fluids and stress on the structure can all spur corrosion. According to the McNally Institute website, the rate of corrosion attack doubles with every 18 F (10°C) rise in temperature. That can be caused by friction between parts as well.

The following table from ASM (American Society for Metals) shows the approximate maximum service temperatures at which various grades of stainless resist oxidation in dry air. The temperatures depend on the actual environmental conditions; in some instances, even lower temperatures will result in oxide scaling.

GRADE INTERMITTENT (°C) CONTINUOUS (°C)
304 870 925
309 980 1095
310 1035 1150
316 870 925
321 870 925
410 815 705
416 760 675
420 735 620
430 870 815
2111HTR 1150 1150

Table Credit: ASM Metals Handbook