NACE (National Association of Corrosion Engineers) standards focus on the performance of materials in corrosive environments, especially for steel pipes in the oil and gas industry. Its specific requirements for steel pipe performance usually involve the following aspects:
1. Corrosion resistance
Steel pipes must be able to resist corrosion in specific corrosive environments, such as the presence of hydrogen sulfide (H₂S) and carbon dioxide (CO₂), and require steel pipes to maintain structural integrity and function in environments containing these corrosive media.
2. Chemical composition control
Limit the content of elements that may affect corrosion resistance in steel pipes, such as sulfur, phosphorus, etc., to ensure that the chemical composition of the steel pipe meets specific corrosion resistance requirements. For example, API 5L GR. B PSL - 1 NACE straight seam steel pipe, the maximum carbon content of seamless steel pipes is 0.28%, the maximum manganese content is 1.2%, while the maximum carbon content of welded pipes is 0.26%, and the maximum manganese content is also 1.2%.
3. Mechanical properties
Steel pipes need to meet specific tensile strength, yield strength and elongation requirements. For example, API 5L GR. B PSL - 1 NACE straight seam steel pipe, seamless steel pipe and welded pipe have a tensile strength of at least 415MPa and a yield strength of at least 245MPa.
4. Testing and certification
Steel pipes must pass a series of tests, including but not limited to corrosion tests, hydrogen sulfide stress corrosion cracking (HIC) tests, stress-oriented hydrogen induced cracking (SOHIC) tests and corrosion fatigue tests. NACE standards may require third-party certification to ensure that the steel pipe meets the specified performance standards.
5. Manufacturing process
Control the manufacturing process of steel pipes, including material procurement, inspection, processing and manufacturing, welding, heat treatment, machining and surface treatment. The details are as follows:
Material procurement: Select high-quality steel that meets relevant standards such as ASTM to ensure the quality of raw materials for steel pipes.
Material inspection: Conduct quality inspections on raw materials, including chemical composition, physical properties, etc., to ensure that the materials fully meet relevant standards.
Processing and manufacturing: Use high-performance processing equipment and technology to manufacture NACE steel pipes, control the manufacturing process, and ensure quality and reliability.
Welding: Use professional welding machines and welding technology to ensure that NACE steel pipes meet the design requirements and can withstand the given pressure and force.
Heat treatment: Heat treat NACE steel pipes to make their hardness and strength meet the corresponding standards.
Machining: The heat-treated steel pipes are processed by drilling, polishing, chamfering, etc. to form the required size value and surface accuracy.
Surface treatment: Clean, polish and coat the surface of the pipeline to ensure that its surface is smooth, beautiful and has good corrosion resistance.
6. Specific standard requirements
NACE MR0175/ISO 15156: This is one of the most widely used corrosion-resistant material standards in the oil and gas industry, which specifies the chemical composition and performance requirements of materials used in environments containing H₂S
