High-characteristic steel for large-size parts

摘要

High-strength steel of which the chemical composition comprises, by weight:
0.03%≦C<0.2%Si≦0.49%3%
the remainder being iron and impurities resulting from production. Block and plates obtained.

主权项

1. Steel block or plate having a thickness greater than or equal to 20 mm and less than or equal to 1 m, and a composition-comprising, by weight:
0.03%≦C≦0.15% Si≦0.49% 3.2%≦Mn≦4% Ni≦0.9% 1%≦Cr≦5% Mo+W/2≦1% Cu≦0.9% S+Se/2+Te/3<0.020% Al≦0.1%, the remainder being iron and impurities resulting from production; wherein the steel block or plate has a structure consisting of bainite and martensite, and in that the difference in Brinell hardness between the harder regions and the less hard regions of the steel block or plate, resulting from segregated veins, is less than 20% of the average Brinell hardness of the steel block or plate.