Description
Alloy Geek P91 or 9Cr1Mo Steel Certified Reference Material
Alloy P91, also known as ASTM A335 P91, is a high-temperature, ferritic-martensitic alloy steel that is commonly used in power generation and petrochemical industries for applications involving elevated temperatures and high-pressure conditions. It is a part of the ASTM A335 specification, which covers seamless ferritic alloy steel pipe for high-temperature service. It comes in two types, P91 Type 1 and P91 Type two with their chemical differences shown below.
For field verification and PMI work, many customers pair this material with pre-owned handheld XRF analyzers for rapid, on-site analysis.
P91 Certified Chemical Composition| Element | Composition |
| As | 0.006% |
| C | 0.104% |
| Ca | 0.002% |
| Co | 0.013% |
| Cr | 8.72% |
| Cu | 0.093% |
| Fe | Balance (~88.9%) |
| Mn | 0.459% |
| Mo | 0.94% |
| N | 0.0323% |
| Nb | 0.078% |
| Ni | 0.148% |
| O | 0.0025% |
| P | 0.011% |
| S | 0.0036% |
| Sb | 0.0026% |
| Si | 0.345% |
| Sn | 0.0062% |
| Ti | 0.0028% |
| V | 0.214% |
| W | 0.0030% |
Industry Chemical Range: ASTM A335 P91 Type1 vs Type2
Difference in chemical compositions of A335 Gr P91 Seamless Steel Pipe, Type 1 and Type 2:
|
Grade |
UNS Designation |
Chemical Composition % |
|||||||
|
P91 Type 1 |
K91560 |
C |
Mn |
P |
S |
Si |
Ni |
Cr |
Mo |
|
0.08-0.12 |
0.30-0.60 |
0.020 |
0.010 |
0.20-0.50 |
0.40 max |
8.00-9.50 | 0.85-1.05 | ||
|
V |
N |
Al |
Nb |
Ti |
Zr |
Sn |
Sb |
||
|
0.18-0.25 |
0.030-0.070 |
0.02 max |
0.06-010 |
0.01 max |
0.01 max |
_ | _ | ||
|
P91 Type 2 |
K91560 |
C |
Mn |
P |
S |
Si |
Ni |
Cr |
Mo |
|
0.08-0.12 |
0.30-0.50 |
0.020 |
0.005 |
0.20-0.40 |
0.40 max |
8.00-9.50 | 0.85-1.05 | ||
|
V |
N |
Al |
Nb |
Ti |
Zr |
Sn |
Sb |
||
|
0.18-0.25 |
0.035-0.070 |
0.02 max |
0.06-0.10 |
0.01 max |
0.01 max |
0.010 max | 0.003 max | ||
Other names for this alloy:
P91 Type 1, P91 Type 2, Alloy Steel, F9, 9Cr1Mo, UNS K90941, ASTM A335 Grade P91, ASTM A213 Grade T91, ASTM A387 Grade 91, ENX10CrMoVNb9-1, EN 10216-2, ASME SA-335 P91
Available material forms:
- XRF: 1/8" thick disc, 1.5" diameter
- OES: 0.75" thick disc, 1.5" diameter
- Chips: 50g of chips
Due to its high-temperature strength, corrosion resistance, and durability, Alloy P91 is a favored choice for applications involving steam and high-pressure environments, such as in power generation plants. It's important to adhere to proper manufacturing, welding, and heat treatment procedures when using Alloy P91 to ensure its performance and safety in high-temperature applications.
Lead time for these CRMs is typically 4 weeks after receipt of order.
Please Contact Us if you would like to know the specific dimensions of a sample.

