1) Chemical composition(WT% Max)
Grade N C H Fe O Ti
Grade 1 0.03 0.08 0.015 0.20 0.18. balanced
Grade 2 0.03 0.08 0.015 0.30 0.25 balanced
Grade 3 0.05 0.08 0.015 0.30 0.35 balanced
Grade 4 0.05 0.08 0.015 0.50 0.40 balanced

2) Properties
Grade Tesile strength(Min)
Ksi Mpa Yield strength 0.2%(Min)
Ksi Mpa Elongation
(Min) % Reduction of Area
(Min) %
Grade 1 35 240 25 170 24 30
Grade 2 50 345 40 275 20 30
Grade 3 65 450 55 380 18 30
Grade 4 80 550 70 483 15 25