Introduction     The colour formed when  stainless steel is heated, either in a furnace application or in the heat  affected zone of welds, is dependent on several factors that are related to the  oxidation resistance of the steel. The heat tint or temper colour formed is caused  by the progressive thickening of the surface oxide layer and so, as temperature  is increased, the colours change.   Oxidation  resistance of stainless steels     However,  there are several factors that affect the degree of colour change and so there  is no a single table of colour and temperature that represents all cases. The  colours formed can only be used as an indication of the temperature to which  the steel has been heated.     Factors  affecting the heat tint colours formed     Steel composition     The  chromium content is the most important single factor affecting oxidation  resistance. The higher the chromium, the more heat resistant the steel and so  the development of the heat tint colou...
 
 
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