METAL PLATE FOR LASER PROCESSING AND METHOD FOR PRODUCING STAINLESS STEEL PLATE FOR LASER PROCESSING
A metal plate for laser processing (such as a stainless steel plate or a titanium plate) and preferably an austenitic stainless steel plate suitable for use as a metal mask or the like which undergoes fine processing with a laser has an average grain diameter d (μm) and a plate thickness t (μm) which satisfy the equation d≦0.0448·t−1.28.
1 . A metal plate for a laser processed metal mask characterized in that it has an average grain diameter d (μm) and a plate thickness t (μm) satisfying the following Equation (1):
d≦ 0.0448 ·t− 1.28 (1)
2 . A metal plate for a laser processed metal mask as set forth in claim 1 wherein the metal plate is selected from an austenitic stainless steel plate, a ferritic stainless steel plate, and a titanium plate.
3 . A metal plate for a laser processed metal mask as set forth in claim 1 having a pattern of small holes or slits formed by laser processing.
4 . A laser cut metal mask having a plate thickness t of at most 400 μm characterized in that it has an average grain diameter d (μm) and a plate thickness t (μm) satisfying the following Equation (1):
d≦ 0.0448 ·t− 1.28 (1)
5 . A method for producing an austenitic stainless steel plate for a laser processed metal mask characterized by performing hot rolling, cold rolling, and annealing on an austenitic stainless steel to obtain an austenitic stainless steel plate and then subjecting the austenitic stainless steel plate to final cold rolling with a reduction of at least 30% and subsequent annealing at 800-950° C. for 25-70 seconds.
6 . A method as set forth in claim 5 wherein temper rolling with a reduction of at least 20% is carried out after the final cold rolling and subsequent annealing.
7 . A method as set forth in claim 6 wherein stress relief annealing at 500-820° C. for 5-150 seconds is carried out after the temper rolling.