Multiobjective Optimization for Forming Process Parameters of Ultrahigh Strength Steel BR1500HS

Figure 6

Microstructure of BR1500HS under different cooling rate: (a) 20°C/s, (b) 30°C/s, (c) 40°C/s, (d) 50°C/s, (e) 70°C/s, and (f) 100°C/s.

(a)

(b)

(c)

(d)

(e)

(f)