ISO 683-5:2014
(Main)Heat treatable steels, alloy steels and free-cutting steels — Part 5: Nitriding steels
Heat treatable steels, alloy steels and free-cutting steels — Part 5: Nitriding steels
ISO 683-5:2014 gives the technical delivery requirements for semi-finished products (e.g. blooms, billets, slabs), bars, wire rod, hot-rolled plates and hammer or drop forgings manufactured from the nitriding steels and supplied in one of the heat-treatment conditions and surface conditions it specifies. The steels are in general intended for the fabrication of quenched and tempered and, subsequently, nitriding machine parts. The requirements for mechanical properties given are restricted to the specified sizes.
Aciers pour traitement thermique, aciers alliés et aciers pour décolletage — Partie 5: Aciers pour nitruration
General Information
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Standards Content (Sample)
INTERNATIONAL ISO
STANDARD 683-5
First edition
2014-12-01
Heat treatable steels, alloy steels and
free-cutting steels —
Part 5:
Nitriding steels
Aciers pour traitement thermique, aciers alliés et aciers pour
décolletage —
Partie 5: Aciers pour nitruration
Reference number
ISO 683-5:2014(E)
©
ISO 2014
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ISO 683-5:2014(E)
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ISO 683-5:2014(E)
Contents Page
Foreword .iv
1 Scope . 1
2 Normative references . 1
3 Terms and definitions . 2
4 Classification and designation . 2
4.1 Classification . 2
4.2 Designation . 3
5 Information to be supplied by the purchaser. 3
5.1 Mandatory information . 3
5.2 Options/supplementary or special requirements. 3
6 Manufacturing process . 4
6.1 General . 4
6.2 Deoxidization . 4
6.3 Heat treatment and surface condition at delivery . 4
6.4 Traceability of the cast . 4
7 Requirements . 4
7.1 Chemical composition, hardness and mechanical properties . 4
7.2 Machinability . 5
7.3 Cold shearability . 5
7.4 Grain size . 5
7.5 Non-metallic inclusions . 5
7.6 Internal soundness . 5
7.7 Surface quality . 5
7.8 Decarburization . 6
7.9 Shape, dimensions and tolerances . 6
8 Inspection . 6
8.1 Testing procedures and types of documents . 6
8.2 Frequency of testing . 6
8.3 Specific inspection and testing . 7
9 Test methods . 7
9.1 Chemical analysis . 7
9.2 Hardness and mechanical tests . 7
9.3 Retests . 7
10 Marking . 8
Annex A (normative) Ruling sections for mechanical properties .20
Annex B (normative) Supplementary of special requirements .23
Annex C (informative) Designation of steels given in this part of ISO 683 and of comparable
grades covered in various designation systems.25
Annex D (informative) Dimensional standards applicable to products complying with this
part of ISO 683 .26
Bibliography .27
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ISO 683-5:2014(E)
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. 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. 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 on the meaning of ISO specific terms and expressions related to conformity
assessment, as well as information about ISO’s adherence to the WTO principles in the Technical Barriers
to Trade (TBT) see the following URL: Foreword - Supplementary information
The committee responsible for this document is ISO/TC 17, Steel, Subcommittee SC 4, Heat treatable and
alloy steels.
This first edition cancels and replaces ISO 683-10:1987, of which it constitutes a technical revision.
ISO 683 consists of the following parts, under the general title Heat-treatable steels, alloy steels and free-
cutting steels:
— Part 1: Non-alloy steels for quenching and tempering
— Part 2: Alloy steels for quenching and tempering
— Part 3: Case-hardening steels
— Part 4: Free-cutting steels
— Part 5: Nitriding steels
— Part 14: Hot-rolled steels for quenched and tempered springs
— Part 15: Valve steels for internal combustion engines
— Part 17: Ball and roller bearing steels
— Part 18: Bright steel products
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INTERNATIONAL STANDARD ISO 683-5:2014(E)
Heat treatable steels, alloy steels and free-cutting steels —
Part 5:
Nitriding steels
1 Scope
1.1 This part of ISO 683 gives the technical delivery requirements for
— semi-finished products, e.g. blooms, billets, slabs (see Note 1),
— bars (see Note 1),
— wire rod,
— hot-rolled plates (see Note 2), and
— hammer or drop forgings (see Note 1)
manufactured from the nitriding steels listed in Table 3 and supplied in one of the heat-treatment
conditions given for the different types of products in Table 1, lines 2 to 5, and in one of the surface
conditions given in Table 2.
The steels are in general intended for the fabrication of quenched and tempered and, subsequently,
nitriding machine parts.
The requirements for mechanical properties given in this part of ISO 683 are restricted to the sizes
given in Table 6.
NOTE 1 Hammer-forged semi-finished products (blooms, billets, slabs, etc.), seamless rolled rings and hammer-
forged bars are in the following covered under semi-finished products or bars and not under the term “hammer
and drop forgings”.
NOTE 2 The term “plate” includes in the following also wide flats unless otherwise stated.
1.2 In special cases, variations in these technical delivery requirements or additions to these
requirements can form the subject of an agreement at the time of enquiry and order (see Annex B).
1.3 In addition to this part of ISO 683, the general technical delivery requirements of ISO 404 are applicable.
2 Normative references
The following documents, in whole or in part, are normatively referenced in this document and are
indispensable to its application. For dated references, only the edition cited applies. For undated
references, the latest edition of the referenced document (including any amendments) applies.
ISO 148-1, Metallic materials — Charpy pendulum impact test — Part 1: Test method
ISO 377, Steel and steel products — Location and preparation of samples and test pieces for mechanical testing
ISO 404, Steel and steel products — General technical delivery requirements
ISO 643, Steels – Micrographic determination of the apparent grain size
ISO 4885, Ferrous products — Heat treatments — Vocabulary
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ISO 683-5:2014(E)
ISO 4948-1, Steels — Classification — Part 1: Classification of steels into unalloyed and alloy steels based on
chemical composition
ISO 4948-2, Steels — Classification — Part 2: Classification of unalloyed and alloy steels according to main
quality classes and main property or application characteristics
ISO/TS 4949, Steel names based on letter symbols
ISO 6506-1, Metallic materials – Brinell hardness test – Part 1: Test method
ISO 6892-1, Metallic materials – Tensile testing – Part 1: Method of test at room temperature
ISO 6929, Steel products — Vocabulary
ISO 7788, Steel — Surface finish of hot-rolled plates and wide flats — Delivery requirements
ISO 9443, Heat-treatable and alloy steels — Surface quality classes for hot-rolled round bars and wire
rods — Technical delivery conditions
ISO/TR 9769, Steel and iron — Review of available methods of analysis
ISO 10474, Steel and steel products — Inspection documents
ISO 14284, Steel and iron — Sampling and preparation of samples for the determination of chemical composition
3 Terms and definitions
For the purposes of this document, the terms and definitions of ISO 377, ISO 4885, ISO 4948-1, ISO 4948-2,
ISO 6929, ISO 14284 and the following apply.
3.1
ruling section
section for which the specified mechanical properties shall apply
Note 1 to entry: Independent of the actual shape and dimensions of the cross-section of the product, the size of its
ruling section is always given by a diameter. This corresponds to the diameter of an “equivalent round bar”. That
is a round bar which, at the position of its cross-section specified for taking the test pieces for the mechanical
tests, will, when being cooled from austenitizing temperature, show the same cooling rate as the actual ruling
section of the product concerned at its position for taking the test pieces.
3.2
nitriding steel
heat-treatable steel containing controlled amounts of the nitride forming elements, aluminium,
chromium, molybdenum, and/or vanadium and are particularly suited for nitriding
3.3
nitriding
heat treatment characterized by keeping a steel product for a sufficiently long time at temperatures
below the transformation temperature AC1 in a nitrogen providing gaseous or liquid salt environment
to achieve diffusion of the nitrogen into the steel surface
Note 1 to entry: An increase in surface hardness, wear resistance and fatigue properties is attained with this treatment.
4 Classification and designation
4.1 Classification
The classification of the relevant steel grades is allocated in accordance with to ISO 4948-1 and
ISO 4948-2. All steels covered by this International standard are classified as alloy special steels.
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ISO 683-5:2014(E)
4.2 Designation
For the steel grades covered by this document, the steel names as given in the relevant tables are
allocated in accordance with ISO/TS 4949.
5 Information to be supplied by the purchaser
5.1 Mandatory information
The manufacturer shall obtain the following information from the purchaser at the time of enquiry and
order:
a) the quantity to be delivered;
b) the designation of the product form (e.g.: slab, bloom, billet, round bar, wire rod)
c) either the designation of the dimensional standard and the dimensions and tolerances selected from
this (see 7.9) or the designation of the drawing or any other document covering the dimensions and
tolerances required for the product;
d) reference to this part of ISO 683, i.e. ISO 683-5;
e) the designation of the steel grade given in Table 3;
f) designation for a test report 2.2 or, if required any other type of inspection document in accordance
with ISO 10474.
5.2 Options/supplementary or special requirements
A number of options are specified in this part of ISO 683and listed below in this subclause. If the
purchaser does not indicate the wish to implement any of these options, the products will be supplied in
accordance with the basic specification of this part of ISO 683(see 5.1).
a) if a heat-treatment condition other than the untreated condition is required, the symbol for this
other condition (see Table 1, column 2),
b) if another surface condition than hot worked or a special surface quality is required, the surface
condition (see Table 2, column 2) and the surface quality (see 7.7);
c) any supplementary requirement that shall be complied with, the symbol and, where necessary, the
details of this supplementary requirement (see Annex B);
d) any requirement relating to the removal of surface defects (see 7.7.4);
e) any requirement regarding the permissible depth of decarburization (see 7.8);
f) impact test at a temperature lower than room temperature (see 9.2.3).
EXAMPLE 2 t hot rolled round bars according to ISO 1035-1 with a nominal diameter of 40 mm and a nominal
length of 8 000 mm with diameter tolerance according to class S and with length tolerance according to class L2
made of steel grade ISO 683-5 31CrMo12 (see Table 3) in heat-treatment condition +QT (see Table 1) with surface
blast cleaned +BC (see Table 2) and with an inspection document 2.2.
Round bars ISO 1035 - 40,0S × 8 000L2
ISO 683-5 - 31CrMo12+QT
inspection document ISO 10474 2.2
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ISO 683-5:2014(E)
6 Manufacturing process
6.1 General
The manufacturing process of the steel and of the products is with the restrictions given by the
requirements in 6.2 and 6.4, left to the discretion of the manufacturer.
6.2 Deoxidization
All steels shall be deoxidized.
6.3 Heat treatment and surface condition at delivery
6.3.1 Normal condition at delivery
Unless otherwise agreed at the time of enquiry and order, the products shall be delivered in the untreated,
i.e. hot-worked condition.
6.3.2 Particular heat-treatment condition
If so agreed at the time of enquiry and order, the products shall be delivered in one of the particular heat-
treatment conditions given in Table 1, lines 3 to 5.
6.3.3 Particular surface conditions
If so agreed at the time of enquiry and order, the products shall be delivered in another particular surface
condition as given in Table 2, line 3 to 6.
6.4 Traceability of the cast
Each product shall be traceable to the cast, see Clause 10.
7 Requirements
7.1 Chemical composition, hardness and mechanical properties
7.1.1 General
Table 1 shows the combinations of usual heat-treatment conditions at delivery, product forms and
requirements as specified in Tables 3 to 6.
7.1.2 Chemical composition
The chemical composition determined by cast analysis shall comply with the values in Table 3.
Permissible deviations between the limiting values for cast analysis and the values for product analysis
are given in Table 4.
The product analysis shall be carried out when specified at the time of enquiry and order (see B.4).
7.1.3 Mechanical properties
The requirements for the mechanical properties are for steels delivered in the “soft annealed condition”
(+A) according to the maximum Brinell hardness, see Table 5 and for steels delivered in the “quenched
and tempered condition” (+QT) according to the values cited in Table 6.
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ISO 683-5:2014(E)
7.2 Machinability
All steels are in the condition: “soft annealed” (+A) machinable.
Where a further improved machinability is required special heat treatments may be agreed at the time
of enquiry and order.
7.3 Cold shearability
Under suitable shearing conditions (avoiding local stress peaks, preheating, application of blades with a
profile adapted to that of the product, etc.), all steels are shearable in the “soft annealed” (+A) condition.
7.4 Grain size
Unless otherwise agreed at the time of enquiry and order, the steel shall show a fine grain structure with
an austenitic grain size of 5 and finer, when tested in accordance with ISO 643. For verification see B.2.
The ferrite content in the core of the quenched and tempered product shall be determined on one
microsection per cast, dimension and heat treatment batch, if agreed at the time of enquiry and order.
7.5 Non-metallic inclusions
7.5.1 Microscopic inclusions
The special steels shall have a certain degree of cleanness; however, verification of the non-metallic
inclusion content requires a special agreement. If there is such an agreement at the time of enquiry and
order, the microscopic non-metallic inclusion content shall be determined to an agreed procedure and
within agreed limits in accordance with ISO 4967 or another standard, e.g. regional standards EN 10247
or JIS G 0555.
7.5.2 Macroscopic inclusions
This requirement is applicable to the verification of the macroscopic inclusions in special steels. If
verification is agreed, the method and acceptance limits shall be agreed at the time of enquiry and order.
7.6 Internal soundness
The steels shall be free from internal defects likely to have an adverse effect (see Annex B, Clause B.3).
7.7 Surface quality
7.7.1 All products shall have a smooth surface finish appropriate to the manufacturing processes applied.
7.7.2 Minor surface imperfections which may occur under normal manufacturing conditions, such as
prints originating from rolled-in scale, are not to be regarded as defects.
7.7.3 Bars and wire rod are delivered with surface class A accordance with ISO 9443 and hot-rolled
plates and wide flats shall be delivered with a surface in accordance with ISO 7788, unless otherwise
agreed at the time of enquiry and order.
Where no International Standard on the surface quality of steel products exists, detailed requirements
referring to this characteristic shall, where appropriate, be agreed at the time of enquiry and order.
It is more difficult to detect and eliminate surface discontinuities from coiled products than from cut
lengths. This should be taken into account when agreements on surface quality are made.
NOTE Bars and wire rod for cold heading and cold extrusion are covered fully by ISO 4954.
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ISO 683-5:2014(E)
7.7.4 The removal of surface defects by welding shall only be permitted with the approval of the
customer or his/her representative.
If surface discontinuities are repaired, the method and maximum depth of removal shall be agreed at
the time of enquiry and order.
7.8 Decarburization
Requirements relating to the permissible depth of decarburization may be agreed at the time of
enquiry and order.
The depth of decarburization shall be determined in accordance with the micrographic method
specified in ISO 3887.
7.9 Shape, dimensions and tolerances
The shape, dimensions and tolerances of the products shall comply with the requirements agreed at
the time of enquiry and order. The agreements shall, as far as possible, be based on corresponding
International Standards (see Annex D), otherwise on suitable national standards.
8 Inspection
8.1 Testing procedures and types of documents
8.1.1 Products complying with this part of ISO 683 shall be ordered and delivered with one of the
inspection documents as specified in ISO 10474. The type of document shall be agreed upon at the time of
enquiry and order. If the order does not contain any specification of this type, a test report 2.2 shall be issued.
8.1.2 If, in accordance with the agreements made at the time of enquiry and order, a test report 2.2 is to
be provided, this shall cover following information:
a) Confirmation that the material complies with the requirements of the order;
b) Results of the cast analysis for all elements specified in Table 3 for the steel grade concerned.
8.1.3 If in accordance with the agreements in the order an inspection certificate 3.1 or 3.2 is to be
provided, the specific inspections and tests described in 8.2, 8.3 and 9 shall be carried out and the results
shall be confirmed in the inspection certificate.
In addition the inspection certificate shall cover:
c) Confirmation that the material complies with the requirements of the order;
d) Results of the cast analysis for all elements specified in Table 3 for the steel grade concerned;
e) The result of all inspections and tests ordered by supplementary requirements (see Annex B);
f) The symbol letters or numbers relating the inspection certificate, test pieces and products to each other.
8.2 Frequency of testing
The amount of testing, the sampling conditions and the test methods to be applied for the verification of
compliance with the requirements shall be in accordance with the prescriptions of Table 8.
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ISO 683-5:2014(E)
8.3 Specific inspection and testing
8.3.1 Verification of the hardness and mechanical properties
The hardness requirements and/or mechanical properties given for the relevant treatment condition in
Table 1, column 8, sub-column 2, shall be verified, with the following exception. The requirements given
in footnotes a to Table 1 (mechanical properties of reference test pieces), shall only be verified if the
supplementary requirement given in Annex B, Clause B.1 is ordered.
8.3.2 Visual and dimensional inspection
A sufficient number of products shall be inspected to ensure compliance with the specification.
9 Test methods
9.1 Chemical analysis
The choice of a suitable physical or chemical analytical method for the analysis shall be at the discretion
of the manufacturer. In cases of dispute, the method for product analysis used shall be agreed taking
into account the relevant existing International Standards.
NOTE The list of available International Standards on chemical analysis is given in ISO/TR 9769.
9.2 Hardness and mechanical tests
9.2.1 Hardness
For products in the “soft annealed” condition (+A), the hardness shall be measured in accordance
with ISO 6506-1.
9.2.2 Mechanical tests
For products in the “quenched and tempered” condition (+QT) the tensile test shall be carried out in
accordance with ISO 6892-1.
For the specified yield strength in the tables of mechanical properties in this part of ISO 683, the upper
yield strength, R , shall be determined.
eH
If a yield phenomenon is not present, the 0,2 % proof strength, R , shall be determined.
p0,2
9.2.3 Impact test
The impact test shall be carried out in accordance with ISO 148-1.
At the time of enquiry and order, additional requirements concerning the impact energy and the
verification at temperatures other than room temperature (0 °C, –20 °C and –40 °C) can be agreed.
NOTE Impact values at lower temperatures cannot be achieved for all steel grades.
The average values of a set of three test pieces shall be equal to or greater than the specified value. One
individual value may be below the specified value, provided it is not less than 70 % of that value.
If these conditions are not satisfied, the sample product is rejected and retests may be carried out on the
remainder of the test unit.
9.3 Retests
Retests for steels for quenching and tempering and criteria should be as specified in ISO 404.
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ISO 683-5:2014(E)
10 Marking
The manufacturer shall mark the products or the bundles or boxes containing the products in a suitable
way, so that the identification of the cast, the steel type and the origin of the delivery is possible (see
Annex B, Clause B.6).
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ISO 683-5:2014(E)
Table 1 — Combination of usual heat-treatment conditions at delivery, product forms and
requirements according to Tables 3 to 6
1 2 3 4 5 6 7 8 9
x = applicable
...
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