| 摘要 |
<p>PROBLEM TO BE SOLVED: To establish a laser beam cutting method of a thick steel plate so as not to have slag adhesion and not generate a notch. SOLUTION: In a laser beam cutting method to laser beam cut a thick steel plate by using a laser beam cutting nozzle constituting of a double tube shape in which a cutting gas oxygen is injected from a center nozzle 2 together with a laser beam 1 and a shield oxygen gas is injected from an auxiliary nozzle 3, whereas a diameter of a cutting oxygen gas injection port 6 of the center nozzle 2 is D mm, a width of a shield oxygen gas injection port 7 of the auxiliary nozzle 3 is W mm, a thickness of the cutting oxygen gas injection port is (h) mm, a plate thickness of a steel plate to be cut is (t) mm, the relation of respective dimensions satisfies the formula (1)-(3) in the following. D>=0.05t...(1) W>=0.5D...(2) 0.5<=h<=1.0...(3).</p> |
