Boiler vessel grade SB450 steel plate

1. SB450 steel plate belongs to boiler vessel plate, which implements JIS G3103 standard. SB450 plate has higher strength, hardness, wear resistance and good toughness. Its hardenability is slightly higher than 40Cr, and its critical hardenability diameter in oil is 18-33mm; the machinability is good after normalizing, cold drawn, thread rolling, tapping, forging and heat treatment performance are also good. The tendency of grain growth, oxidation, decarburization and quenching deformation at high temperature are all small; but it has temper brittleness.

2. Chemical composition of SB450 steel plate:
C: 0.42-0.3
S ：≤0.035
P: ≤0.035
Cr: ≤0.25
Ni: ≤0.25
Cu: ≤0.25

3. Mechanical properties of SB450 steel plate:
(1) Tensile strength ≥620(63)
(2) Yield strength: ≥375(38)
(3) Elongation: ≥15 Reduction of area: ≥40
(4) Impact energy: ≥39
(5) Impact toughness value: ≥49(5)
(6) Annealed steel ≤217HB hot fire

4.Application of SB450 steel plate: The temperature range of SB450 is -20 - 425℃. It mainly replaces 40Cr steel to make medium and small section quenched and tempered parts, such as automobile half shaft, steering shaft, worm, spline shaft and machine tool spindle. SB450 steel can also be used instead of 40CrNi steel when making smaller parts.