Question

When a low carbon steel is heated up to upper critical temperature :

• A. There is no change in grain size
• B. The average grain size is a minimum
• C. The grain size first increases and then decreases very rapidly
• D. The grain size increases very rapidly

Answer 1

The correct option is B The average grain size is a minimum

When a low varbon steel is healed upto upper critical temperature the average grain size is a minimum.