Main chemical composition (%)?
C≤0.20; Mn=1.00~1.60; Si≤0.50; S≤0.035; P≤0.035; trace amounts of V/Nb/Ti.
Functions of each element?
Mn: Strengthening and toughening; Si: Deoxidation strengthening; S/P: Impurities, lower values result in better toughness; V/Nb/Ti: Refining grain size and strengthening.
S/P limits for different grades?
A/B: S≤0.040, P≤0.040
C: S/P≤0.035
D: S/P≤0.030
E: S/P≤0.025.
Carbon equivalent?
Approximately 0.45%~0.49%, weldability is acceptable, thick plates require preheating.
Hazardous element control?
S≤0.035%, P≤0.035%, to prevent hot brittleness/cold brittleness.