EXTRALOW-SILICON HIGH-TOUGHNESS CAST STEEL FOR HIGH TEMPERATURE AND HIGH PRESSURE USE

摘要

PURPOSE:To obtain a cast steel with superior characteristics at high temp. and superior toughness at low temp. by reducing the Si content of a Cr-Mo or Cr- Mo-V cast steel having a specified composition. CONSTITUTION:This cast steel consists of, by weight, 0.10-0.30% C, =0.10% Si, 0.50-1.50% Mn, 0.25-3.00% Cr, 0.10-1.00% Ni, 0.25-1.50% Mo and the balance Fe. The macro-segregation of the cast steel is reduced, and the notch toughness is improved without deteriorating the characteristics at high temp. such as the creep rupture strength, so the cast steel has superior characteristics at high temp. and superior toughness at low temp. Said characteristics and toughness are not generally obtd. at the same time.