NACE MR0175-2021 (ISO 15156-1-2-3-2020) PDF

Full title and description

St NACE MR0175-2021 (ANSI/NACE MR0175-2021) — Petroleum and natural gas industries — Materials for use in H2S‑containing environments in oil and gas production; aligned with ISO 15156 Parts 1, 2 and 3 (ISO 15156‑1:2020, ISO 15156‑2:2020, ISO 15156‑3:2020). This consolidated publication provides requirements and recommendations for selection and qualification of carbon and low‑alloy steels, corrosion‑resistant alloys and other metallic materials for service in H2S‑containing environments where failure could endanger personnel, the public or the environment.

Abstract

NACE MR0175-2021 brings the NACE MR0175 content into technical alignment with the ISO 15156:2020 series (Parts 1–3). It addresses cracking mechanisms associated with H2S service (sulfide stress cracking, stress corrosion cracking, hydrogen‑induced cracking, stepwise cracking, SOHIC, soft‑zone cracking and galvanically induced hydrogen stress cracking) and gives selection/qualification rules and recommendations for materials used in oil and gas production and natural‑gas treatment plants. The publication is typically supplied as a single consolidated set (three parts) and may include Technical Circulars and errata.

General information

• Status: Current (NACE MR0175-2021 aligning with ISO 15156:2020; supersedes the MR0175/ISO 15156‑2015 set).
• Publication date: NACE MR0175‑2021 — 2021; ISO 15156 parts 1/2/3 — 2020.
• Publisher: NACE International (published in ANSI/NACE format for the U.S. market).
• ICS / categories: 75.180.01, 75.180.10 (petroleum and natural gas equipment), and related ICS for corrosion of metals (e.g., 77.060).
• Edition / version: NACE MR0175 edition 2021 (technical alignment to ISO 15156 Parts 1–3, edition 2020; ISO parts generally listed as edition 4, 2020).
• Number of pages: Combined Parts 1–3 (consolidated package) — approximately 139 pages (Part 1 ~20 pages, Part 2 ~48 pages, Part 3 ~71 pages); final page count may vary depending on whether Technical Circulars and errata are included.

Scope

This standard gives principles, requirements and recommendations for the selection and qualification of metallic materials for equipment used in oil and natural gas production and natural‑gas treatment plants in H2S‑containing environments. It is intended to prevent cracking failures (SSC, SCC, HIC, SWC, SOHIC, soft‑zone cracking and related mechanisms) in equipment whose failure could affect health, safety or the environment. The document supplements, but does not replace, materials requirements in design codes or national regulations and is primarily applicable to load‑controlled designs (with guidance for strain‑based design in Part 1).

Key topics and requirements

• Definitions and general principles for selection of cracking‑resistant materials for H2S service.
• Assessment procedures for service environments (H2S content, CO2, chloride, pH, temperature, pressure) and their effect on material selection.
• Qualification and limits on carbon and low‑alloy steels (testing, material grades, heat treatment and use of cast irons).
• Requirements and guidance for corrosion‑resistant alloys (CRAs) and other alloys (composition, fabrication and testing criteria).
• Procedures for laboratory testing, inspection and acceptance criteria to demonstrate resistance to H2S‑related cracking mechanisms.
• Annexes/annex tables listing candidate materials and application notes; Technical Circulars provide clarifications and interim updates.

Typical use and users

Engineers and materials/corrosion specialists in upstream oil and gas operators, EPC contractors, fabricators, inspection authorities and third‑party certifiers use MR0175/ISO 15156 to select and qualify materials for wells, surface production equipment, piping, pressure‑containing systems and gas‑treatment equipment exposed to sour (H2S‑bearing) environments. It is also used by standards committees, procurement teams and regulatory compliance groups working on safe materials selection for sour service.

Related standards

ISO 15156 is part of a family of materials and corrosion standards for oil & gas. Commonly referenced or related documents include: the earlier MR0175/ISO 15156‑2015 set (superseded), technical circulars and corrigenda to ISO 15156:2020, NACE/AMPP testing methods and other NACE/ISO documents on corrosion monitoring and materials testing (for example, guidance on sucker‑rod equipment in NACE MR0176 and various NACE test methods).

Keywords

H2S, sour service, sulfide stress cracking (SSC), stress corrosion cracking (SCC), hydrogen‑induced cracking (HIC), materials selection, corrosion‑resistant alloys (CRAs), carbon steels, low‑alloy steels, oil and gas, ISO 15156, NACE MR0175, qualification, sour environments.

FAQ

Q: What is this standard?

A: NACE MR0175-2021 is the NACE/ANSI publication that aligns NACE MR0175 with the ISO 15156:2020 three‑part series (Parts 1–3) for materials for use in H2S‑containing environments in oil and gas production.

Q: What does it cover?

A: It covers principles, requirements and recommendations for selecting and qualifying metallic materials (carbon/low‑alloy steels, CRAs and other alloys) for sour (H2S‑containing) service, with a focus on preventing H2S‑related cracking mechanisms and specifying test/acceptance criteria.

Q: Who typically uses it?

A: Materials and corrosion engineers, design and procurement teams, fabricators, inspection bodies and regulators in upstream oil & gas and natural gas treatment operations use this standard to ensure materials are suitable for sour service.

Q: Is it current or superseded?

A: The 2021 NACE MR0175 edition (aligned to ISO 15156:2020) supersedes the earlier MR0175/ISO 15156 2015 set and is the current consolidated reference; users should also track Technical Circulars/corrigenda published after 2020 for clarifications and interim changes.

Q: Is it part of a series?

A: Yes — it is the NACE/ANSI presentation of the ISO 15156 series, which consists of three parts (Part 1: general principles; Part 2: carbon/low‑alloy steels & cast irons; Part 3: CRAs and other alloys). Technical Circulars accompany the parts to provide maintenance clarifications.

Q: What are the key keywords?

A: H2S, sour service, sulfide stress cracking, hydrogen‑induced cracking, stress corrosion cracking, CRA, carbon steel, material qualification, oil & gas production, ISO 15156, NACE MR0175.