Do you use stainless steel in some of your metal fabrication processes? Have you noticed some discolouration? Discussed below are strategies that can help in preventing the material from being discoloured as it is exposed to heat.
Pay Attention to the Chromium Content
An oxide layer is normally formed when heated metal reacts with oxygen to form an oxide. The discolouration is a result of the formation of that oxide layer. One way to reduce the likelihood of surface oxidation is by selecting stainless steel with a high chromium content. For example, stainless steel that has 10-percent chromium is likely to form a heat tint faster than stainless steel with 13-percent chromium content.
Keep Oxygen Away
You can also reduce the likelihood of the heat tint forming by taking steps to exclude oxygen from your fabrication processes. For instance, welders can use a shielding gas to limit the degree to which oxygen in ordinary air can react with the stainless steel during the process of welding the metal.
Reduce Exposure Durations
Heat tint can be prevented by managing how long stainless steel is exposed to heat and oxygen. The likelihood of tint formation increases as the duration of exposure increases. You should, therefore, limit how long stainless steel is exposed to heat to protect it from developing a heat tint. For instance, don't preheat the stainless steel for long in case your fabrication process requires you to preheat the metal. Consult the product data sheets about the safe preheat durations for the specific type of stainless steel that you are working with.
Mind the Surface Finish
The surface finish of stainless steel can also contribute towards delaying or accelerating the onset of heat tint formation. For example, stainless steel with a rough surface is likely to develop heat tint faster than stainless steel with a smooth surface because the rough surface provides a larger surface area for heat to penetrate the material and cause the formation of an oxide layer. Opt for stainless steel with a smooth surface in case your fabrication processes will entail subjecting that material to intense heat.
Talk to stainless manufacturing professionals about how you can treat your steel products in order to eliminate the heat tint in case the tint is marring the visual appeal of your finished products. Make sure you implement all their suggestions so that the oxide layer doesn't compromise the corrosion resistance of the stainless steel.