Laser Treatment for Strengthening of Thin Sheet Steel

Figure 7

Microstructure of steel: (a) untreated area of steel with ferrite-pearlite structure (65% ferrite and 35% pearlite according to GOST 8233-56 [40], grain size G8 according to ISO 643:2012 [42], magnification ×1500), (b) laser-treated layer (dispersed sorbite structure, grain size G11 according to ISO 643:2012 [42], magnification ×1500), and (c) laser-treated layer (dispersed sorbite structure, according to GOST 8233-56 [40], magnification ×20000).