Specific features of laser cutting of steel sheets and monitoring of sample quality after laser influence

Abstract

An automated laser system with an 8-kW quantum generator with the beam quality not worse than that of a single-mode laser is described. The possibility of using such a system in procurement production for cutting carbon and stainless steel sheets is demonstrated. The quality control of the blank material shows that the properties of the latter satisfy appropriate standards.Key words: industrial gas lasers, self-filtered resonators, gas-laser cutting of metal sheets, technological parameters, structure and properties of blanks.Introduction. Among laser technologies currently used in machine-building branches of industry, gaslaser cutting of metal and nonmetal materials has found the widest application [1-3]. The use of laser cutting in procurement production turned out to be most effective [1]. A wide range of thicknesses and grades of materials being cut and almost arbitrary parameters of blanks being cut allow manufacturing blanks of various types, sizes, and geometry.The main advantages of laser cutting are as follows: -improvement of processing quality owing to the minimum area of thermal influence, reduction of heatinduced strains, absence of the force action on the article; -higher processing rate (severalfold higher than that in conventional methods of mechanical treatment); -severalfold reduction of time needed for the preparatory stage of production in the case new articles are to be produced; -higher material utilization rate owing to the use of optimal cutting patterns; -high quality of cutting of structural steels, which often allows butt welding without prior mechanical treatment;-no displacements of the cut edges; -possibility of producing articles with notches in the form of acute angles, junctions without radii, and thin bridge connections (less than 1-2 mm thick), as well as small-diameter orifices (in contrast to die-cutting by universal circular tools).Using the laser-cutting technology, one can cut sheeted materials over a complicated contour with accuracy ranging from 100 to several micrometers.Advanced laser cutting systems allow cutting thin-sheeted materials with a velocity up to 120 m/min with an error smaller than 100 µm. To reach a maximum possible thickness of sheets being cut and a maximum possible cutting velocity, the laser power should be increased; therefore, the technology of laser cutting with a power of 5 to 6 kW has been recently conquered in industry.

Analysis of laser cutting speed influence on the surface quality and shape deviation of steel parts

“…For laser cutting of stainless steel and plastics there are similar influences of laser cutting speed, power of laser beam as well as purity or pressure of assist gas like for the cutting sheets made of the carbon steel. The better surface roughness is for a quantum laser than for a CO2 gas laser cutter at the same cutting parameters [13][14][15][16][17][18][19][20][21][22][23][24][25][26][27][28][29][30][31] .…”