Boiler quality 15Mo3 steel was the designation in DIN 17155, replaced in 1993 by EN 10028-2. At the same time, the name was changed to 16Mo3, maintaining the steel number 1.5415. There are small differences in minimum values between boiler quality 15Mo3 and 16Mo3 pressure vessel steel plate.
15Mo3 VS 16Mo3 steel plate in chemical composition:
| Grade | C | Si | Mn | P | S | Cr | Cu | Mo | Ni | N |
| 15Mo3 | 0.12-0.20 | 0.10-0.35 | 0.40-0.90 | ≦0.035 | ≦0.030 | ≦0.25 | ≦0.30 | ≦0.30 | ||
| 16Mo3 | 0.12-0.20 | ≦0.35 | 0.40-0.90 | ≦0.025 | ≦0.010 | ≦0.30 | ≦0.30 | 0.25-0.35 | ≦0.30 | ≦0.012 |
15Mo3 VS 16Mo3 steel plate in mechanical properties:
| Grade | Yield Strength | Tensile Strength | Elongation |
| (Mpa) | (MPa) | (%) | |
| 15Mo3 | ≧275 | 440-590 | ≧20 |
| 16Mo3 | ≧275 | 440-590 | ≧22 |
16Mo3 pressure vessel steel, designated with steel number 1.5415, is an European (DIN EN) steel grade for alloy steels. 16Mo3 pressure vessel steel plate is Cr-Mo alloy steel. The addition of molybdenum (Mo) not only improves the resistance of 16Mo3 pressure vessel steel plate to pitting corrosion, but also significantly enhances creep strength of 16Mo3 pressure vessel steel plate at elevated temperatures. The chromium(Cr) improves the resistance of 16Mo3 pressure vessel steel plate to high-temperature hydrogen attack and graphitization.
Key Similarities & Differences
Standards: 15Mo3 belongs to German DIN 17155, while 16Mo3 is under European EN 10028-2.
Composition: Both contain about 0.25-0.35% Molybdenum (Mo) for high-temperature strength and corrosion resistance.
Equivalence: 16Mo3 is the direct equivalent of 15Mo3, with 16Mo3 often having stricter limits for P (Phosphorus) and S (Sulfur) for better weldability.
Applications: Both are ideal for boilers, pressure vessels, and superheaters in power generation and chemical industries.
