| 摘要 |
<p>PROBLEM TO BE SOLVED: To detect contact with a cutter with certainty and to secure difficult cutting property by regulating Brinell hardness, elongation, and plate thickness to values in respectively specified ranges, specifying the relationship between plate thickness and hardness, and further properly regulating a composition. SOLUTION: The Brinell hardness of this steel plate and its plate thickness are regulated, respectively, to 40 to 150 and 6 to 50 mm, and, as a numerical formula, HB<=HBt is satisfied [where HBt is defined by HBt=100+2(t-9) and HB and (t) are Brinell hardness and plate thickness (mm), respectively], and also elongation is regulated to 40 to 80%. As to the composition of the steel plate, it is preferable that the steel plate contains, as basic composition, 0.0005-0.05% C, 0.001-1.0% Si, 0.01-0.6% Mn, <=0.05% P, <=0.03% S, 0.001-0.1% T, <=0.02% f(c), and <=0.1% Ceq and further contains one or >=2 kinds among 0.005-0.05% Nb, 0.001-0.05% V, 0.02-0.5% Cr, and 0.005-0.5% Mo and has the balance Fe. Further, if necessary, either or both of 0.05-1.0% Cu and 0.05-1.5% Ni are incorporated.</p> |
