The main characteristics of ASTM A691 9Cr steel pipe are reflected in its chemical composition and physical properties. The chromium content of this steel pipe is approximately 9%, with an appropriate amount of molybdenum. This alloy combination endows the material with excellent high-temperature strength and creep resistance. In working environments above 600°C, the 9Cr steel pipe can still maintain good mechanical properties, which is incomparable to ordinary carbon steel. Additionally, the addition of chromium significantly improves the corrosion resistance of the steel pipe, enabling it to resist the erosion of corrosive media such as hydrogen sulfide and carbon dioxide. In terms of physical properties, the tensile strength of ASTM A691 9Cr steel pipe is typically in the range of 415-585 MPa, with a yield strength of no less than 205 MPa and an elongation rate of over 20%. These indicators ensure the safe use of the steel pipe under high-pressure conditions.
The production process has a decisive impact on the performance of ASTM A691 9Cr longitudinal welded steel pipe. GNEE Group adopts advanced hot rolling technology, precisely controlling the rolling temperature and deformation amount to optimize the internal microstructure of the steel pipe. Longitudinal welding is a key link in the manufacturing process, commonly using high-frequency resistance welding (ERW) or submerged arc welding (SAW) technology to ensure that the weld quality meets or exceeds that of the parent material. The heat treatment process includes steps such as normalizing and tempering, which can eliminate welding stress, refine grain size, and further improve the comprehensive performance of the steel pipe. A strict quality control system runs through the entire production process, including multiple links such as chemical composition analysis, mechanical property testing, non-destructive testing, and hydrostatic testing, ensuring that each steel pipe meets the requirements of ASTM A691 standard.
Astm a691 gr 9cr specifications
Steel Pipe Plates and Standards
| Steel Pipe Grade | Steel Type | Plate Standard ASTM | Plate Grade | Hardness HB max |
|---|---|---|---|---|
| 9CR | 9% Chromium, 1% Molybdenum Steel | A387/A387M | Grade 9 | 241 |
Heat Treatment Parameters
| Pipe Grade | ASTM Standard | Postweld Heat Treatment Temp. (Stress Relieving) °F (°C) | Normalizing Temp. max unless otherwise specified °F (°C) | Quenching Temp. max unless otherwise specified °F (°C) | Tempering Temp. min °F (°C) |
|---|---|---|---|---|---|
| 9CR | A387/A387M | 1325～1375 (715～745) * | - | 1325～1375 (715～745) * | - |
Astm a691 gr 9cr equivalent
|
Pipe Grade |
Type of Steel |
ASTM Specification |
HB, max |
|
|
Number |
Grade |
|||
|
9 CR |
9 % chromium, 1 % molybdenum steel |
A387/A387M |
9 |
241 |
A691 GR 9CR Alloy STEEL EFW PIPEs Factory
