6. Which of the following temperatures represents the tempering temperature for C 30 steel?
A. 860-890?C
B. 550-660?C
C. 1400-1450?C
D. 1700?C
6. Which of the following temperatures represents the tempering temperature for C 30 steel?
A. 860-890?C
B. 550-660?C
C. 1400-1450?C
D. 1700?C