prEN ISO 15156-1

SLOVENSKI STANDARD
01-marec-2026
Naftna in plinska industrija, vključno z nizkoogljično energijo - Materiali za
uporabo v okoljih s H2S v proizvodnji olja in plina - 1. del: Zahteve glede
materialov in obdelave materialov (ISO/DIS 15156-1:2025)
Oil and gas industries including lower carbon energy - Materials for use in H2S-
containing environments in oil and gas production - Part 1: Materials and materials
processing requirements (ISO/DIS 15156-1:2025)
Erdöl- und Erdgasindustrie - Werkstoffe für den Einsatz in H2S-haltiger Umgebung bei
der Öl- und Gasgewinnung - Teil 1: Allgemeine Grundlagen für die Auswahl von gegen
Rissbildung beständigen Werkstoffen (ISO/DIS 15156-1:2025)
Industries du pétrole et du gaz naturel - Matériaux pour utilisation dans des
environnements contenant de l'hydrogène sulfuré (H2S) dans la production de pétrole et
de gaz - Partie 1: Exigences relatives aux matériaux et au traitement des matériaux
(ISO/DIS 15156-1:2025)
Ta slovenski standard je istoveten z: prEN ISO 15156-1
ICS:
75.180.01 Oprema za industrijo nafte in Equipment for petroleum and
zemeljskega plina na splošno natural gas industries in
general
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

DRAFT
International
Standard
ISO/DIS 15156-1
ISO/TC 67
Oil and gas industries including
Secretariat: NEN
lower carbon energy — Materials
Voting begins on:
for use in H2S-containing
2025-12-17
environments in oil and gas
Voting terminates on:
production —
2026-03-11
Part 1:
Materials and materials processing
requirements
ICS: 75.180.01
THIS DOCUMENT IS A DRAFT CIRCULATED
FOR COMMENTS AND APPROVAL. IT
IS THEREFORE SUBJECT TO CHANGE
AND MAY NOT BE REFERRED TO AS AN
INTERNATIONAL STANDARD UNTIL
PUBLISHED AS SUCH.
This document is circulated as received from the committee secretariat.
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Reference number
ISO/DIS 15156-1:2025(en)
DRAFT
ISO/DIS 15156-1:2025(en)
International
Standard
ISO/DIS 15156-1
ISO/TC 67
Oil and gas industries including
Secretariat: NEN
lower carbon energy — Materials
Voting begins on:
for use in H2S-containing
environments in oil and gas
Voting terminates on:
production —
Part 1:
Materials and materials processing
requirements
ICS: 75.180.01
THIS DOCUMENT IS A DRAFT CIRCULATED
FOR COMMENTS AND APPROVAL. IT
IS THEREFORE SUBJECT TO CHANGE
AND MAY NOT BE REFERRED TO AS AN
INTERNATIONAL STANDARD UNTIL
PUBLISHED AS SUCH.
This document is circulated as received from the committee secretariat.
IN ADDITION TO THEIR EVALUATION AS
BEING ACCEPTABLE FOR INDUSTRIAL,
© ISO 2025
TECHNOLOGICAL, COMMERCIAL AND
USER PURPOSES, DRAFT INTERNATIONAL
All rights reserved. Unless otherwise specified, or required in the context of its implementation, no part of this publication may
STANDARDS MAY ON OCCASION HAVE TO
ISO/CEN PARALLEL PROCESSING
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BE CONSIDERED IN THE LIGHT OF THEIR
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Published in Switzerland Reference number
ISO/DIS 15156-1:2025(en)
ii
ISO/DIS 15156-1:2025(en)
Contents Page
Foreword .vi
Introduction .vii
1 Scope . 1
2 Normative references . 1
3 Terms and definitions . 3
4 Symbols and abbreviated terms.10
5 General principles . 10
6 Chemical composition requirements .13
6.1 General . 13
6.2 Carbon and low alloy steels.14
6.2.1 General .14
6.2.2 Requirements for flat-rolled products .14
6.2.3 Requirements for wrought products, excluding flat rolled.14
6.3 Cast irons .14
6.4 Stainless steels .14
6.4.1 General .14
6.4.2 Austenitic stainless steels . 15
6.4.3 Highly alloyed austenitic stainless steels . 15
6.4.4 S13Cr martensitic stainless steels . 15
6.5 Nickel-based alloys . 15
6.5.1 Solid-solution nickel-based alloys . 15
6.5.2 Precipitation-hardened nickel-based alloys .16
6.6 Other alloys.16
7 Hardness requirements . 16
7.1 General .16
7.2 Conversions .16
7.3 Base metal hardness testing .16
7.4 Incidental work hardening .17
7.5 Weld hardness testing .17
7.5.1 General .17
7.5.2 Hardness testing for verification of a welding procedure.17
7.5.3 Hardness surveys for verification of a welding procedure .18
8 Carbon and low alloy steels and cast irons .23
8.1 General requirements for carbon and low alloy steels . 23
8.2 Cast irons for general applications . 23
8.3 Materials processing requirements for bar, forgings and tubular products for downhole
equipment . 23
8.3.1 General . 23
8.3.2 API 5CT (ISO 11960) products . 23
8.3.3 Bar, forgings and mechanical tubing .24
8.4 Drilling components . 26
8.5 Cast iron packer and subsurface components . 26
8.6 Compressors and pumps . 26
8.7 Line pipe and piping steels . 26
8.7.1 General . 26
8.7.2 Material for restricted service conditions . 26
8.8 Pressure vessel steels.27
8.9 Welding carbon and low alloy steels and cast irons .27
9 Corrosion-resistant alloys and other alloys .28
9.1 Austenitic stainless steels . 28
9.1.1 General . 28

iii
ISO/DIS 15156-1:2025(en)
9.1.2 Material, condition and applications for austenitic stainless steels . 28
9.1.3 Welding austenitic stainless steels . 29
9.1.4 Equipment or component specific requirements . 29
9.2 Highly alloyed austenitic stainless steels . 29
9.2.1 General . 29
9.2.2 Materials processing requirements for highly alloyed austenitic stainless steels
used in any equipment or components . 30
9.2.3 Welding highly alloyed austenitic stainless steels . 30
9.2.4 Equipment or component specific requirements . 30
9.3 Duplex stainless steels . 30
9.3.1 Requirements for duplex stainless steels used in any equipment or components. 30
9.3.2 Welding of duplex stainless steels . 30
9.3.3 Specific requirements for downhole tubular components and other subsurface
equipment .31
9.4 Ferritic stainless steels .31
9.5 Martensitic stainless steels .31
9.5.1 Materials processing requirements for martensitic stainless steels used in any
equipment or components .31
9.5.2 Welding martensitic stainless steels .32
9.5.3 Equipment or component specific requirements .32
9.6 Precipitation-hardened austenitic stainless steels . 33
9.6.1 Materials processing requirements for any equipment or components. 33
9.6.2 Welding precipitation-hardened austenitic stainless steels . 33
9.7 Precipitation-hardened martensitic stainless steels . 33
9.7.1 General requirements . 33
9.7.2 Welding precipitation hardenable martensitic stainless steels . 33
9.7.3 Wellhead and tree components (valve bore sealing mechanisms, choke trim
and stems) and subsurface equipment . 34
9.7.4 Non-pressure containing internal valve, pressure regulator, and level-controller
and miscellaneous equipment . 34
9.7.5 Snap rings . 34
9.7.6 Compressor components . 34
9.8 Solid-solution nickel-based alloys . 34
9.8.1 Materials processing requirements for solid-solution nickel-based alloys used
in any equipment or components . 34
9.8.2 Welding of solid-solution nickel-based alloys. 35
9.8.3 Bearing pins . 35
9.9 Precipitation-hardened nickel-based alloys . . 35
9.9.1 Material processing requirements for precipitation-hardened nickel-based
alloys used in any equipment or components . 35
9.9.2 Welding precipitation hardening nickel-based alloys . .37
9.9.3 Alternative requirements for specific components .37
9.10 Titanium alloys .37
9.10.1 Material processing requirements for titanium alloys used in any equipment or
components .37
9.10.2 Welding titanium alloys . 38
9.11 Cobalt-based alloys . 38
9.11.1 Material processing requirements for cobalt-based alloys used in any equipment
or components . 38
9.11.2 Welding cobalt-based alloys . 38
9.11.3 Equipment or component specific requirements . 38
9.12 Other alloys. 39
9.12.1 Tantalum alloys . 39
9.12.2 Copper and aluminium alloys . 39
9.12.3 Wear resistant alloys used for sintered, cast or wrought components . 39
9.12.4 Welding other alloys. 39
10 Material processing requirements .39
10.1 General . 39

iv
ISO/DIS 15156-1:2025(en)
10.2 Welding . . 39
10.2.1 General . 39
10.2.2 Carbon and low alloy steels and cast irons . 40
10.2.3 Corrosion-resistant and other alloys . 40
10.3 Surface treatments .41
10.3.1 General .41
10.3.2 Nitriding .41
10.3.3 Boriding .41
10.3.4 Brazing .42
10.3.5 Other surface modification processes .42
10.4 Corrosion-resistant claddings and linings .42
10.5 Corrosion-resistant weld overlays .42
10.5.1 Requirements for substrates .42
10.5.2 Requirements for overlays .43
10.6 Hardfacing coatings and overlays, and wear-resistant inserts .43
10.7 Other fabrication methods .43
10.8 Cold work and deformation . . 44
10.8.1 General . 44
10.8.2 Carbon alloy steels . 44
10.8.3 Corrosion-resistant and other alloys . 44
10.9 Other processes . 44
10.9.1 Additive manufacturing (AM) . 44
10.9.2 Threading, marking and stamping . 44
Bibliography .46

v
ISO/DIS 15156-1:2025(en)
Foreword
ISO (the International Organization for Standardization) is a worldwide federation of national standards
bodies (ISO member bodies). The work of preparing International Standards is normally carried out through
ISO technical committees. Each member body interested in a subject for which a technical committee
has been established has the right to be represented on that committee. International organizations,
governmental and non-governmental, in liaison with ISO, also take part in the work. ISO collaborates closely
with the International Electrotechnical Commission (IEC) on all matters of electrotechnical standardization.
The procedures used to develop this document and those intended for its further maintenance are described
in the ISO/IEC Directives, Part 1. In particular the different approval criteria needed for the different types
of ISO documents should be noted. This document was drafted in accordance with the editorial rules of the
ISO/IEC Directives, Part 2 (see www.iso.org/directives).
Attention is drawn to the possibility that some of the elements of this document may be the subject of patent
rights. ISO shall not be held responsible for identifying any or all such patent rights. Details of any patent
rights identified during the development of the document will be in the Introduction and/or on the ISO list of
patent declarations received (see www.iso.org/patents).
Any trade name used in this document is information given for the convenience of users and does not
constitute an endorsement.
For an explanation of the voluntary nature of standards, the meaning of ISO specific terms and expressions
related to conformity assessment, as well as information about ISO's adherence to the World Trade
Organization (WTO) principles in the Technical Barriers to Trade (TBT), see www.iso.org/iso/foreword.html.
This document was prepared by Technical Committee ISO/TC 67, Oil and gas industries including lower carbon
energy, in collaboration with the European Committee for Standardization (CEN) Technical Committee CEN/
TC 12, Oil and gas industries including lower carbon energy, in accordance with the Agreement on technical
cooperation between ISO and CEN (Vienna Agreement).
This fifth edition cancels and replaces the fourth edition (ISO 15156-1:2020), which has been technically
revised. The main changes compared to the previous edition are as follows:
— this is a rewritten and reorganized edition with main changes compared to the previous editions;
— ISO 15156 series consists of the following parts:
— Part 1: Materials and materials processing requirements;
— Part 2: Service environment assessment and material selection;
— Part 3: Verification, qualification and balloting requirements.
— there are references to ISO and API standards such as API 5CRA, ISO 13680 and API 6ACRA for many of
the nickel-based alloys and some 13Cr stainless steels (UNS S41425, UNS S41426 and UNS S41427) that
define material requirements;
— welding, coatings and overlays have been expanded for CRAs;
— additive manufacturing is included in 10.9.1;
— requirements added for high strength low alloy steel accessories;
— for a list of permitted exclusions see ISO 15156-2:202x, Clause 1.
A list of all parts in the ISO 15156 series can be found on the ISO website.
Any feedback or questions on this document should be directed to the user’s national standards body. A
complete listing of these bodies can be found at www.iso.org/members.html.

vi
ISO/DIS 15156-1:2025(en)
Introduction
The consequences of sudden failures of metallic oil and gas field components, associated with their exposure
to H S-containing production fluids, led to the preparation of the first edition of ANSI/NACE MR0175, which
was published in 1975 by the National Association of Corrosion Engineers, now known as AMPP (Association
for Materials Protection and Performance). Collaboration with the European Federation of Corrosion (EFC)
resulted in the first joint publication of the ISO 15156 series in 2003.
The fifth edition of the ISO 15156 series makes substantive changes to the structure of the standard and is
organized as follows:
— Part 1: Materials and materials processing requirements;
— Part 2: Service environment assessment and material selection;
— Part 3: Verification, qualification, and balloting requirements.
Material specification requirements are given in ISO 15156-1. This includes requirements that are generic to
a material class and those that are specific to a material listed in ISO 15156-2. In some instances, specifically
for those grades whose performance in H S-containing environments is most susceptible to materials
processing variation, ISO 15156-1 also specifies materials processing or qualification requirements for a
listed material.
Acceptable materials selections for a given combination of equipment and service environment are stated
in ISO 15156-2: it lists environmental limits for materials that have been accepted through the development
and maintenance of the ISO 15156 series, and stipulates the path to acceptance for materials and/or
environmental conditions not listed.
The processes and procedures for verification and qualification by H S-testing (including where required
by ISO 15156-1 and ISO 15156-2) are given in ISO 15156-3. Processes and procedures for balloting new
materials, material conditions, environmental limits, and/or product specifications for incorporation into
the ISO 15156 series are also described in ISO 15156-3. A description of the process by which changes are
approved can be found at the ISO 15156 maintenance website www.iso.org/iso15156maintenance.
Conformance with the ISO 15156 series can require conformance with more than one document in the
ISO 15156 series. Paths for conformance with the ISO 15156 series are given in Figure 1.

vii
ISO/DIS 15156-1:2025(en)
a
See exclusions in ISO 15156-2:202x, Table 1.
b
There is an option to ballot for inclusion in the ISO 15156 series.
Figure 1 — Paths for conformance with the ISO 15156 series
The ISO 15156 series were developed and approved by representative groups from within the oil and gas
production industry, following the applicable ISO and ANSI/AMPP rules.
Future changes to the ISO 15156 series may be published as interim updates to this document in the form of
ISO Technical Circulars. Document users should check for applicable ISO Technical Circulars when applying
the ISO 15156 series.
ISO 15156-3 describes the requirements for balloting changes based on test data and/or field experience
(e.g. new materials, alternative requirements or alternative limits).
The joint ISO 15156 and ANSI/NACE MR0175/ISO 15156 Maintenance Agency at DIN was set up after
approval by the ISO Technical Management Board given in document 34/2007. This document describes the
makeup of the agency, which includes experts from AMPP and ISO/TC 67, and the process for approval of
ISO Technical Circulars. It is available from the ISO 15156 maintenance website and from the ISO/TC 67
Secretariat. The website also provides access to related documents that provide more detail on ISO 15156
series maintenance activities.
In this document, the following verbal forms are used:
— “shall” indicates a requirement;
— “should” indicates a recommendation;
— “may” indicates a permission;

viii
ISO/DIS 15156-1:2025(en)
— “can” indicates a possibility or a capability.

ix
DRAFT International Standard ISO/DIS 15156-1:2025(en)
Oil and gas industries including lower carbon energy —
Materials for use in H2S-containing environments in oil and
gas production —
Part 1:
Materials and materials processing requirements
WARNING — Metallic materials specified in this document are suitable for H S-containing
environments in oil and gas production but are not necessarily immune to cracking under all service
conditions. It is the equipment user's responsibility to ensure that the materials selected are suitable
for the intended service in accordance with ISO 15156-2.
1 Scope
This document specifies requirements and gives recommendations for the manufacture and processing of
metallic materials for service in equipment used in oil and gas production in H S-containing environments,
where the failure can pose a risk to the functionality of the equipment, to the health and safety of the public
and personnel or to the environment. It supplements, but does not replace, the materials specification
requirements given in the appropriate design codes, standards, or regulations.
This document addresses the metallurgical, manufacturing and quality assurance / control testing
requirements, for carbon and low alloy steels, cast irons, corrosion-resistant alloys and other alloys selected
in accordance with ISO 15156-2:202x, Annex A or Annex B.
Materials selection is not addressed; material selection requirements, including permitted exclusions for
specific categories of equipment, specific applications and specific environments are defined in ISO 15156-2.
Qualification of materials, manufacturing processes and/or materials specifications that are not listed in
this document, are also not addressed (see ISO 15156-3 for qualification and verification of alternative
materials, material selection limits, manufacturing processes or materials specifications).
Additive manufactured (AM) equipment and components are out of scope of this document.
2 Normative references
The following documents are referred to in the text in such a way that some or all of their content constitutes
requirements of this document. For dated references, only the edition cited applies. For undated references,
the latest edition of the referenced document (including any amendments) applies.
ISO 6506-1, Metallic materials — Brinell hardness test — Part 1: Test method
ISO 6507-1, Metallic materials — Vickers hardness test — Part 1: Test method
ISO 6508-1, Metallic materials — Rockwell hardness test — Part 1: Test method
ISO 11960:2020, Petroleum and natural gas industries — Steel pipes for use as casing or tubing for wells
ISO 13680:2024, Oil and gas industries including lower carbon energy — Corrosion-resistant alloy seamless
products for use as casing, tubing, coupling stock and accessory material — Technical delivery conditions
ISO 15156-2:202x, Oil and gas industries including lower carbon energy — Materials for use in H S-containing
environments in oil and gas production — Part 2: Service environment assessment and material selection

ISO/DIS 15156-1:2025(en)
ISO 15156-3:202x, Oil and gas industries including lower carbon energy — Materials for use in H S-containing
environments in oil and gas production — Part 3: Verification, qualification and balloting requirements
1)
API 5CRA:2022 , Corrosion-resistant Alloy Seamless Products for Use as Casing, Tubing, Coupling Stock, and
Accessory Material
API 5CT, Casing and Tubing
API 6ACRA:2025, Age-hardened Nickel-based Alloys for Oil and Gas Drilling and Production Equipment
2)
ASME Boiler and Pressure Vessel Code, Section IX: Welding, Brazing, and Fusing Qualifications —Qualification
Standard for Welding, Brazing, and Fusing Procedures; Welders; Brazers; and Welding, Brazing, and Fusing
Operators
3)
ASTM E10 , Standard Test Method for Brinell Hardness of Metallic Materials
ASTM E18, Standard Test Method for Rockwell Hardness of Metallic Materials
ASTM A48, Standard Specification for Gray Iron Castings
ASTM E92, Standard Test Methods for Vickers Hardness and Knoop Hardness of Metallic Materials
ASTM A182/A182M, Standard Specification for Forged or Rolled Alloy and Stainless Steel Pipe Flanges, Forged
Fittings, and Valves and Parts for High-Temperature Service
ASTM A193, Standard Specification for Alloy-Steel and Stainless Steel Bolting for High Temperature or High
Pressure Service and Other Special Purpose Applications
ASTM A194, Standard Specification for Carbon Steel, Alloy Steel, and Stainless Steel Nuts for Bolts for High
Pressure or High Temperature Service, or Both
ASTM A213/A213M, Standard Specification for Seamless Ferritic and Austenitic Alloy-Steel Boiler, Superheater,
and Heat-Exchanger Tubes
ASTM A220, Standard Specification for Pearlitic Malleable Iron
ASTM A255:2020, Standard Test Methods for Determining Hardenability of Steel
ASTM A278, Standard Specification for Gray Iron Castings for Pressure-Containing Parts for Temperatures Up
to 650 °F (350 °C)
ASTM A320, Standard Specification for Alloy-Steel and Stainless Steel Bolting for Low-Temperature Service
ASTM A351, Standard Specification for Castings, Austenitic, for Pressure-Containing Parts
ASTM A395, Standard Specification for Ferritic Ductile Iron Pressure-Retaining Castings for Use at Elevated
Temperatures
ASTM A536, Standard Specification for Ductile Iron Castings
ASTM E562, Standard Test Method for Determining Volume Fraction by Systematic Manual Point Count
ASTM A571/A571M, Standard Specification for Austenitic Ductile Iron Castings for Pressure-Containing Parts
Suitable for Low-Temperature Service
ASTM A602, Standard Specification for Automotive Malleable Iron Castings
ASTM A743, Standard Specification for Castings, Iron-Chromium, Iron-Chromium-Nickel, Corrosion Resistant,
for General Application
1) www .api .org
2) www .asme .org
3) www .astm .org
ISO/DIS 15156-1:2025(en)
ASTM A744, Standard Specification for Castings, Iron-Chromium-Nickel, Corrosion Resistant, for Severe Service
ASTM A747/A747M, Standard Specification for Steel Castings, Stainless, Precipitation Hardening
ASTM E1245, Standard Practice for Determining the Inclusion or Second-Phase Constituent Content of Metals by
Automatic Image Analysis
4)
BS 4HR-100 , Aerospace series. Procedure for inspection, testing and acceptance of wrought heat-resisting alloys
5)
IOGP S-735 , Supplementary Specification to API Specification 5CT Casing and Tubing
6)
SAE AMS2430 , Shot Peening
3 Terms and definitions
For the purposes of this document, the following terms and definitions apply.
ISO and IEC maintain terminological databases for use in standardization at the following addresses:
— ISO Online browsing platform: available at https:// www .iso .org/ obp
— IEC Electropedia: available at https:// www .electropedia .org/
3.1
additive manufacturing
AM
process of building materials (3.39) to make equipment and components from 3D model data, usually layer
upon layer
3.2
ageing
change in metallurgical properties that generally occurs slowly at ambient temperature (natural ageing)
and more rapidly at higher temperature (artificial ageing)
3.3
anneal
heat to and hold at a temperature appropriate for the specific material (3.39) and then cool at a suitable
rate for purposes such as avoiding undesired phases, recrystallizing, reducing hardness, improving
machineability, or obtaining desired properties
3.4
austenite
face-centred cubic crystalline phase of iron-based alloys
3.5
boriding
boronizing
thermochemical treatment of a workpiece to enrich its surface with boron
Note 1 to entry: The medium in which boriding takes place should be specified, e.g. pack boriding, paste boriding, etc.
[SOURCE: ISO/TS 6084:2022, 3.1.4]
3.6
Brinell hardness
HBW
hardness value, measured in accordance with ISO
...