MATERIALS ENGINEERING – DAY 8

Review of Cold Work and Annealing Demonstration Metal Processing Examples

REVIEW QUESTIONS

What is cold work (CW) and how is it used in metal processing?

What is annealing and how is it used in metal processing?

Name three phenomena associated with the annealing process. Describe what happens to the Cold Worked metal as each occurs.

SAMPLE COLD WORK CALCULATION

Can you calculate the cold work associated with cold rolling a 0.25 inch thick plate down to a thickness of 0.15 inches?

EXAMPLE PROBLEM – BASED ON FIGURE 7.19A copper wire must be drawn to a diameter of 1/8 inches.

We are starting with stock having diameter of 1.0 inches. The wire’s final %EL ductility must be greater than 20%. The yield strength must exceed 30 ksi. Describe the processing of this wire. (Maybe multiple steps?)

EXAMPLE PROBLEM – BASED ON FIGURE 7.19 – FINAL STEP OF CW

Observe that 10% < %CW < 16%. Settle on 13%. Calculate the diameter at the start of the final step.

EXERCISE CONTINUED.

diameter0.125

0.13401 130.17751 430.25103 500.35501 500.50206 500.71002 500.99423 49

We can see that a number of steps of cold work followed by annealing must be carried out.

The %CW is arbitrary excep in the last step, in which we have to go with 13% CW