JIS G3103-07 Carbon Steel and Molybdenum Alloy Steel Plate for Boilers and Other Pressure Vessels SB450M 0.90 max 0.28max - 0.31max 0.15 25<t≦50 0.33max 0.40 t≦25 t≦25 1.20 max 0.030 max 0.030 max 0.20max 25<t≦40 0.23max 0.90 max 245 min 265 min 0.18max 25<t≦38 0.21max 0.45 255 min 0.60 275 min ~ Yield point N/mm² 225 min 25<t≦50 0.31max t≦25 SB480M Mo 450 ~ t≦25 S 590 480 ~ 25<t≦50 0.27max P 620 450 ~ SB480 0.24max Mn 590 480 620 19min No.1A 23min No.10 17min No.1A 21min No.10 19min No.1A 23min No.10 17min No.1A 21min No.10 180° t≦25 25<t≦50 0.75t 1.00t t≦25 25<t≦50 1.00t 1.00t t≦25 25<t≦38 0.50t 0.75t t≦25 25<t≦40 0.75t 1.00t Transverse to rolling direction SB450 t≦25 Si ~ SB410 C ~ Grade Tensile Test Bend Test Tensile Elongation Test Bend Thickness Inside Test Strength % Piece Angle (mm) Radius Piece N/mm² 410 No.1A 21min t≦25 0.5t 25<t ≦ 50 0.75t No.10 25min 550 ~ Chemical Composition % Thickness (mm) Remarks: 1.For SB450 of over 25mm in thickness, the content of C may be designated to be within 0.30%, and that of Mn may be within 1.00%. 2.For tension test pieces, No.1A test piece shall be used for the steel plates of 50mm or under in thickness and No.10 test piece for that over 50mm. However, for the steel plates over 40mm in thickness, No.10 test piece may be used. 3.The elongation of No.1A test piece cut off from the steel plate under 8mm in thickness shall be the values in the above Table reduced by 1% for every decrease of 1mm of thickness or its fraction. 4.The elongation of No.10 test piece cut off from the steel plate over 90mm in thickness shall be the values in the above Table reduced by 0.5% for every increase of 12.5mm of thickness or its fraction. However, the reduction shall be limited to 3%. 5.The bend test may be omitted unless otherwise specified by the purchaser. 6.When the elongation of No.1A test piece cut off from SB450M and SB480M steel plates of over 6 mm to and excluding 20 mm in thickness is more than the value specified in the above Table subtracted by 3, the test piece shall be accepted despite the above specification. Provided that the value of elongation in the guage length of 50 mm including the broken part is 25% or over. 7.Grade SB480M shall be normalized if exceeding 38mm in thickness.