P355NL1 and P460NL2 are specific grades of weldable, fine-grain steel for pressure equipment (boilers, vessels) under EN 10028-3, distinguished by strength and low-temperature performance, with 'P' for pressure, the number for minimum yield strength (355 or 460 MPa), and 'NL2' indicating superior impact toughness at -50°C compared to 'NL1' at -40°C, making them suitable for different cold environments. P460NL2 offers higher strength (460 MPa minimum yield) and better low-temp properties than P355NL1 (355 MPa minimum yield).
Chemical Composition
|
P355NL1 Chemical Composition |
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|
Grade |
The Element Max (%) |
||||||
|
C |
Si |
Mn |
P |
S |
Al(min) |
N |
|
|
P355NL1 |
0.18 |
0.50 |
0.9-1.70 |
0.03 |
0.020 |
|
0.02 |
|
Cr |
Cu |
Mo |
Nb |
Ni |
Ti |
V |
|
|
0.30 |
0.30 |
0.08 |
0.005 |
0.50 |
0.03 |
0.10 |
|
|
P460NL2 Chemical Composition |
|||||||
|
Grade |
The Element Max (%) |
||||||
|
C |
Si |
Mn |
P |
S |
Al(min) |
N |
|
|
P460NL2 |
0.20 |
0.60 |
1.0-1.70 |
0.025 |
0.015 |
|
0.025 |
|
Cr |
Cu |
Mo |
Nb |
Ni |
Ti |
V |
|
|
0.30 |
0.70 |
0.10 |
0.005 |
0.80 |
0.03 |
0.20 |
|
Mechanical Property
|
Grade |
|
P355NL1 Mechanical Property |
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|
Thickness |
Yield |
Tensilmie |
Elongation |
Impact Energy(KV J) min |
|||
|
P355NL1 |
mm |
Min Mpa |
Mpa |
Min % |
-20° |
0° |
+20° |
|
≤ 16 |
355 |
490-630 |
22 |
47 |
55 |
63 |
|
|
16> to ≤35 |
355 |
490-630 |
22 |
47 |
55 |
63 |
|
|
35> to ≤50 |
345 |
490-630 |
22 |
47 |
55 |
63 |
|
|
50> to ≤70 |
325 |
490-630 |
22 |
47 |
55 |
63 |
|
|
70> to ≤100 |
315 |
470-610 |
21 |
47 |
55 |
63 |
|
|
100> to ≤150 |
295 |
450-590 |
21 |
47 |
55 |
63 |
|
|
Grade |
|
P460NL2 Mechanical Property |
|||||
|
Thickness |
Yield |
Tensilmie |
Elongation |
Impact Energy(KV J) min |
|||
|
P460NL2 |
mm |
Min Mpa |
Mpa |
Min % |
-20° |
0° |
+20° |
|
≤ 16 |
460 |
570-720 |
17 |
65 |
90 |
100 |
|
|
16> to ≤35 |
450 |
570-720 |
17 |
65 |
90 |
100 |
|
|
35> to ≤50 |
440 |
570-720 |
17 |
65 |
90 |
100 |
|
|
50> to ≤70 |
420 |
570-720 |
17 |
65 |
90 |
100 |
|
|
70> to ≤100 |
400 |
540-710 |
16 |
65 |
90 |
100 |
|
|
100> to ≤150 |
380 |
520-690 |
16 |
65 |
90 |
100 |
|
Key Characteristics:
Standard: EN 10028-3 (Steels for pressure purposes).
Type: Weldable, fine-grain, normalized (N or NL).
Applications: Boilers, heat exchangers, pressure vessels, pipes for hot liquids/gases.
P355NL1:
Strength: Minimum yield strength around 355 MPa (for thinner plates).
Low-Temp: Impact tested at -40°C or above (NL1).
Use: Good for demanding industrial applications in colder conditions.
P460NL2:
Strength: Higher strength, minimum yield around 460 MPa.
Low-Temp: Tested at -50°C or above (NL2), offering superior cold resistance.
Composition: Tighter control on elements like Phosphorus (P) and Sulfur (S) for better properties.
Use: For extreme cold, high-stress pressure applications.
