Quench and temper heat treatment

Quench and Temper Heat Treatment. After the wheels are heated above the A-3 line on an iron-carbon/cementite phase diagram, quick quenching in a facility reduces tire temperature below 200 F to transform austenite to martensite, which is very hard and brittle. To toughen the martensite so that it can resist wear and accept shock, it is necessary to temper the load by raising its temperature to somewhere in the range of 1000 F to 1290 F (538 C to 699 C) depending on the final product use. 

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