Material NACE MR0175 / ISO 15156 compliance
Are you Still confused when talking about the material with NACE MR0175 compliance?
What is NACE MR0175?
NACE is shorted for National Association of Corrosion Engineers,which was first issued in 1975 . NACE MR 0175 is titled: Petroleum and Natural Gas Industries — Materials for use in H2S-containing environments in oil and gas production. It was issued as a recommendation of threshold limits of H2S above which precautions against environmental cracking are considered necessary. In 2003, a similar document was issued to cover the refining industry, NACE MR0103 Materials Resistant to Sulfide Stress Cracking in Corrosive Petroleum Refining Environments. Also in 2003, MR0175 was adopted by ISO and designated as ISO 15156.
NACE MR0175/ISO 15156 gives requirements and recommendations for the selection and qualification of carbon and low-alloy steels, corrosion-resistant alloys, and other alloys for service in equipment used in oil and natural gas production and natural gas treatment plants in H2S-containing environments,
NACE-MR-0175 lists the requirements for carbon steels, low alloys and corrosion resistant alloys. For each material group, NACE MR0175 provides the following metallurgical requirements:
- Chemistry
- Hardness
- Heat treatment
- HIC resistance etc
NACE MR0175 also provides the environment limits i.e, amount of H2S expressed as partial pressure, the maximum chloride content, pH range etc.
A NACE MR0175 compliant material (sometimes inaccurately referred to as NACE material or NACE piping) is a material that meets all the requirements of NACE MR0175 and can be used in H2S environments within the limits set by the standard.
NACE MR0175 Pipe and Fittings
Steel pipe and related fittings which are made from the NACE material (complied with NACE MR 0175 or ISO 15156 standard). We call them NACE pipe, or NACE pipe fittings.
Therefore, these products are specially used in the oil and gas environments that contain the H2S etc corrosive chemicals.
ASTM A350. LF2 requires thehardnessto be 197 HB maximum and this meets therequirementsforcarbon steelforgings inNACE MR0175/ISO 15156-2.
| Steel Type | Grades Included | Comments |
| Ferritic | 405,430, 409, 434, 436, 442, 444, 445, 446, 447, 448 | Hardness up to 22 HRC |
| Martensitic | 410, 420 | Hardness up to 22 HRC |
| Martensitic | F6NM | Hardness up to 23 HRC |
| Martensitic | S41425 | Hardness up to 28 HRC |
| Austenitic | 201, 202, 302, 304, 304L, 305, 309, 310, 316, 316L, 317, 321, 347, S31254(254SMO), N08904(904L), N08926(1925hMo) | Solution annealed, no cold work to enhance properties, hardness up to 22 HRC |
| Austenitic | S20910 | Hardness up to 35 HRC |
| Duplex | S31803 (1.4462), S32520 (UR 52N+), S32750 (2507), S32760 (Zeron 100), S32550(Ferralium 255) | PREN >30 solution annealed condition, ferrite content 35% to 65%, or 30 to 70% in welds. Note that the general restriction of 28 HRC in previous editions is not found in this latest edition of the standard. There is a specific restriction on HIP’d S31803 to 25HRC. For some applications cold worked material is allowed up to 36HRC |
| Precipitation Hardening | 17-4 PH | 33 HRC Age hardening at 620 deg C |
| Precipitation Hardening | S45000 | 31 HRC Age hardening at 620 deg C |
| Precipitation Hardening | S66286 | 35 HRC |
Free machining grades such as the 303 and 416 types are excluded from of NACE MR 0175/ISO 15156