| 摘要 |
PROBLEM TO BE SOLVED: To obtain a primer treated steel sheet excellent in layer cuttability by coating a steel having a specified compsn. with a primer agent satisfying specified relation as for the compositional ratio therein and the amt. to be coated. SOLUTION: A laser cutting steel is coated with a primer agent so as to satisfy the conditions of Zn<=40g/m<2> and Zn+8(SiO2 )<=50g/m<2> . The components of the steel are composed of the ones contg., by weight, 0.02 to 0.30% C, <=0.3% Si and 0.3 to 1.6% Mn, furthermore contg. one or >= two kinds among <=1% Ni, <=1% Cu, <=1% Mo and <=0.5% Cr, and the balance Fe with inevitable impurities. The range of the temp. at which laser cutting is possible highly depends on the amt. of Zn+8(SiO2 ), and in the case of <=20g/m<2> , it hardly changes, but in the case of >50g/m<2> , the cuttable speed rapidly decreases. The steel for shipbuilding, bridges or the like free from rust and high in the quality of the cut face is obtd. |
