- The piece is heated to a cherry red colour and then cooled rapidly in water oils and brine.
- At the cherry red colour the steel will have undergone structural changes (FCC to BCC, martensite) and the rapid cooling does not allow it to revert to its original condition.
- Very hard and Brittle.
- It is done by heating the article to a suitable temperature (500°C) below the reddening point of steel and then cooling it in oil or water.
- The higher the temperature the greater the reduction in hardness and brittleness.
- The temperature is gauged by... (More)