Depth and performance of laser cutting heat affected zone of cold rolled sheet

In order to determine the depth of laser cutting heat affected zone and the influence of laser cutting heat affected zone on the mechanical properties of cold rolled sheet products with different thickness and strength, the laser cutting test of cold rolled sheet products was carried out by changing the laser cutting rate, and the microstructure, depth and tensile properties of the heat affected zone after laser cutting were studied. The results show that the heat affected zone could be divided into two parts. The first part was the melting zone at the edge of the laser kerf, and the second part was the non-melting zone. The melting zone was mainly martensite, and the non-melting zone was mainly martensite + bainite. The faster the laser cutting rate, the smaller the depth of the heat affected zone of the cold rolled sheet, the higher the strength of the cold rolled sheet or the thicker the thickness, and the greater the depth of the heat affected zone. The yield strength and tensile strength of laser cutting samples were higher than those of machining center samples, and the elongation after fracture was lower. With the increase of steel grade, the difference between the two was increasing.