kSIST FprEN 16079:2022
(Main)Founding - Compacted (vermicular) graphite cast irons
Founding - Compacted (vermicular) graphite cast irons
This document defines the grades and the corresponding requirements for compacted (vermicular) graphite cast irons.
This document specifies 4 grades of compacted (vermicular) graphite cast iron by a classification based on the minimum mechanical properties measured on machined test pieces prepared from cast samples or samples cut from a casting.
This document does not cover technical delivery conditions for iron castings (see EN 1559-1 [1] and EN 1559-3 [2]).
Gießereiwesen - Gusseisen mit Vermiculargraphit
Dieses Dokument definiert die Sorten und die entsprechenden Anforderungen an Gusseisen mit Vermiculargraphit.
Dieses Dokument legt 4 Sorten von Gusseisen mit Vermiculargraphit fest, deren Klassifizierung auf den minimalen mechanischen Eigenschaften basiert, die an mechanisch hergestellten Proben aus gegossenen Probestücken oder aus einem Gussstück entnommenen Probestücken gemessen wurden.
Dieses Dokument behandelt nicht die technischen Lieferbedingungen für Gusseisen (siehe EN 1559-1 [1] und EN 1559-3 [2]).
Fonderie - Fontes à graphite vermiculaire (compacté)
Le présent document définit les nuances de fonte à graphite vermiculaire (compacté) et les exigences correspondantes.
Le présent document spécifie 4 nuances de fonte à graphite vermiculaire (compacté) par le biais d’une classification basée sur les propriétés mécaniques minimales, mesurées sur des éprouvettes usinées à partir d’échantillons coulés ou d’échantillons découpés dans une pièce moulée.
Le présent document ne couvre pas les conditions techniques de fourniture des pièces moulées en fonte (voir l’EN 1559 1 [1] et l’EN 1559 3 [2]).
Livarstvo - Železove litine s kompaktnim (vermikularnim) grafitom
General Information
Relations
Standards Content (Sample)
SLOVENSKI STANDARD
oSIST prEN 16079:2021
01-februar-2021
Livarstvo - Železove litine s kompaktnim (vermikularnim) grafitom
Founding - Compacted (vermicular) graphite cast irons
Gießereiwesen - Gusseisen mit Vermiculargraphit
Fonderie - Fontes à graphite vermiculaire (compacté)
Ta slovenski standard je istoveten z: prEN 16079
ICS:
77.080.10 Železo Irons
77.140.80 Železni in jekleni ulitki Iron and steel castings
oSIST prEN 16079:2021 en,fr,de
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.
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oSIST prEN 16079:2021
DRAFT
EUROPEAN STANDARD
prEN 16079
NORME EUROPÉENNE
EUROPÄISCHE NORM
December 2020
ICS 77.080.10 Will supersede EN 16079:2011
English Version
Founding - Compacted (vermicular) graphite cast irons
Fonderie - Fontes à graphite vermiculaire (compacté) Gießereiwesen - Gusseisen mit Vermiculargraphit
This draft European Standard is submitted to CEN members for enquiry. It has been drawn up by the Technical Committee
CEN/TC 190.
If this draft becomes a European Standard, CEN members are bound to comply with the CEN/CENELEC Internal Regulations
which stipulate the conditions for giving this European Standard the status of a national standard without any alteration.
This draft European Standard was established by CEN in three official versions (English, French, German). A version in any other
language made by translation under the responsibility of a CEN member into its own language and notified to the CEN-CENELEC
Management Centre has the same status as the official versions.
CEN members are the national standards bodies of Austria, Belgium, Bulgaria, Croatia, Cyprus, Czech Republic, Denmark, Estonia,
Finland, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway,
Poland, Portugal, Republic of North Macedonia, Romania, Serbia, Slovakia, Slovenia, Spain, Sweden, Switzerland, Turkey and
United Kingdom.
Recipients of this draft are invited to submit, with their comments, notification of any relevant patent rights of which they are
aware and to provide supporting documentation.
Warning : This document is not a European Standard. It is distributed for review and comments. It is subject to change without
notice and shall not be referred to as a European Standard.
EUROPEAN COMMITTEE FOR STANDARDIZATION
COMITÉ EUROPÉEN DE NORMALISATION
EUROPÄISCHES KOMITEE FÜR NORMUNG
CEN-CENELEC Management Centre: Rue de la Science 23, B-1040 Brussels
© 2020 CEN All rights of exploitation in any form and by any means reserved Ref. No. prEN 16079:2020 E
worldwide for CEN national Members.
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Contents Page
European foreword . 4
Introduction . 5
1 Scope . 7
2 Normative references . 7
3 Terms and definitions . 7
4 Designation . 8
5 Order information . 8
6 Manufacture . 9
7 Requirements . 9
7.1 General. 9
7.2 Test pieces machined from separately cast samples . 9
7.3 Test pieces machined from side-by-side and cast-on samples. 9
7.4 Test pieces machined from samples cut from a casting . 10
7.5 Hardness . 11
7.6 Graphite structure . 11
8 Sampling . 11
8.1 General. 11
8.2 Cast samples . 12
8.2.1 Size of cast sample . 12
8.2.2 Frequency and number of tests . 12
8.2.3 Separately cast samples. 12
8.2.4 Side-by-side cast samples . 12
8.2.5 Cast-on samples . 13
8.2.6 Test pieces machined from cast samples . 13
8.3 Samples cut from a casting . 13
9 Test methods . 17
9.1 Tensile test . 17
9.2 Hardness test . 19
9.3 Graphite structure examination . 20
10 Retests . 20
10.1 Need for retests . 20
10.2 Test validity . 20
10.3 Nonconforming test results . 20
10.4 Heat treatment of samples and castings . 20
11 Inspection documentation. 21
Annex A (informative) Additional information on properties and typical applications of
compacted (vermicular) graphite cast irons . 22
Annex B (informative) Compacted (vermicular) graphite cast iron nodularity evaluation . 26
B.1 Nodularity definition . 26
B.2 Factors influencing nodularity . 26
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B.3 Basic method for nodularity evaluation . 26
B.4 Microscope settings for sound nodularity evaluation (see also ISO/TR 945-2) . 26
B.5 Roundness of graphite nodules . 26
B.6 Classification of rounded graphite particles by a shape factor . 27
B.7 Intermediate graphite particles, understanding sterical effects . 27
B.8 Calculation of percentage nodularity . 28
B.9 Location of testing . 28
B.10 Rating chart for determining nodularity in compacted (vermicular) graphite cast
irons . 28
B.11 Rating chart for the roundness of graphite particles, assigning shape factors . 29
Annex C (informative) Guidance values for tensile properties measured on test pieces
machined from samples cut from a casting . 31
Annex D (normative) Sectioning procedure for cast samples . 32
Annex E (informative) Comparison of compacted (vermicular) graphite cast iron material
designations according to EN 1560 and ISO/TR 15931 [4][5] . 33
Annex F (informative) Changes since the last version . 34
Bibliography . 35
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European foreword
This document (prEN 16079:2020) has been prepared by Technical Committee CEN/TC 190 “Foundry
technology”, the secretariat of which is held by DIN.
This document is currently submitted to the CEN Enquiry.
This document will supersede EN 16079:2011.
Within its programme of work, Technical Committee CEN/TC 190 requested CEN/TC 190/WG 5 “Grey
cast iron and compacted graphite cast iron” to prepare EN 16079.
Annex F provides details of significant technical changes between this document and the previous
edition.
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Introduction
This document classifies compacted (vermicular) graphite cast irons (CGI), in accordance with the
mechanical properties of the material.
The properties of compacted (vermicular) graphite cast irons depend on their graphite and matrix
microstructure. A moderate section sensitivity results from different cooling velocities in different wall
thickness of the casting. When designating a material grade it needs consideration.
Table 1 defines material grades according to their mechanical properties.
1) Table 1 designates (verifies) the cast material in the foundry (process quality assurance). The
customer designates the material grade in view of requirements from component design. The
choice of cast samples is based on the relevant wall thickness to ensure comparability.
2) Table 1 defines minimum property values (ultimate tensile strength) for each material grade, based
on cast samples. For the casting itself, typical property values are given in Table C.1.
Cast iron materials are molten from steel scraps of different compositions (circular economy), pig iron,
alloying elements, carburizers, etc., neither using ready alloys nor applying secondary metallurgical
methods. Depending on the production route used, the chemical composition can vary (Clause 6). The
mechanical properties prevail.
Material designation. The customer designates the material grade based on design requirements
(load). In a casting with complex shape and different wall thickness, property values can vary over the
casting, due to section sensitivity. An ‘over all’ designation of the entire casting by only one cast sample
is not representative.
If only one cast sample is possible (e.g. due to cost reasons, space in the mould, or when cutting a
sample from the casting is not possible), then it represents the most interesting, relevant wall thickness.
In case of an inappropriate material designation, the desired properties may not be reached locally, in
the most interesting, relevant section of the cast component.
This can be avoided by co-operation of customer and foundry early in the design stage. The foundry can
control the solidification of the casting and thus fulfil locally required properties.
NOTE The designation system by number is based on the structure and rules of EN 10027-2 [8] and so
corresponds with the European numbering system for steel and other materials.
Property values. The cast sample represents the properties in the relevant wall thickness section of
the casting, given by component design. The minimum tensile properties to be obtained in cast samples
represent recent process ability for all types of compacted graphite cast iron production.
Anticipated values in the casting (Table C.1) are slightly decreasing with increasing wall thickness.
The mechanical properties of the material can be evaluated on machined test pieces prepared from
— separately cast samples,
— side by side cast samples,
— cast-on samples, or
— samples cut from a casting.
For many applications, tensile strength and hardness are not the only properties of interest to casting
designers. Other mechanical or physical properties can be decisive for the use of grey iron.
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Annex A gives additional information on properties and typical applications of compacted (vermicular)
graphite cast irons.
Annex B describes a procedure for the determination of nodularity of the microstructure. It includes
reference images for visual analysis and guidelines for automated image analysis.
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1 Scope
This document defines the grades and the corresponding requirements for compacted (vermicular)
graphite cast irons.
This document specifies 4 grades of compacted (vermicular) graphite cast iron by a classification based
on the minimum mechanical properties measured on machined test pieces prepared from cast samples
or samples cut from a casting.
This document does not cover technical delivery conditions for iron castings (see EN 1559-1 [1] and
EN 1559-3 [2]).
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.
EN 10204, Metallic products — Types of inspection documents
EN ISO 945-1, Microstructure of cast irons — Part 1: Graphite classification by visual analysis (ISO 945-1)
EN ISO 6506-1, Metallic materials — Brinell hardness test — Part 1: Test method (ISO 6506-1)
EN ISO 6892-1, Metallic materials — Tensile testing — Part 1: Method of test at room temperature (ISO
6892-1)
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:
— IEC Electropedia: available at http://www.electropedia.org/
— ISO Online browsing platform: available at https://www.iso.org/obp
3.1
compacted (vermicular) graphite cast iron
cast material, iron and carbon based, the carbon being present mainly in the form of compacted
(vermicular) graphite particles that appear vermicular on a two-dimensional plane of polish, the
graphite particles being embedded in a matrix consisting of ferrite, ferrite/pearlite, or pearlite
Note 1 to entry: Annex B provides typical compacted (vermicular) graphite cast iron microstructures.
3.2
graphite modification treatment
operation that brings the liquid iron into contact with a substance to produce graphite in the
predominantly compacted (vermicular) form during solidification
3.3
nodularity
percentage of spheroidal graphite particles (forms V and VI according EN ISO 945-1)
Note 1 to entry: Graphite particles in compacted (vermicular) graphite cast irons are predominantly of form III.
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Note 2 to entry: A technique for evaluating the nodularity of compacted (vermicular) graphite cast irons is
described in Annex B.
3.4
cast sample
quantity of material cast to represent the cast material, including separately cast sample, side by side
cast sample and cast-on sample
3.5
separately cast sample
sample cast in a separate sand mould under representative manufacturing conditions and material
grade
3.6
side-by-side cast sample
sample cast in a mould alongside the casting, with a joint running system
3.7
cast-on sample
sample attached directly to the running system or the casting
3.8
sample cut from a casting
sample cut from an individual casting, by agreement between the manufacturer and the purchaser
3.9
relevant wall thickness
wall thickness representative of the casting, defined for the determination of the size of the cast
samples to which the mechanical properties apply
4 Designation
The material shall be designated either by symbol or by number as given in Table 1.
As a section sensitive material, Table 1 illustrates the wall thickness dependence of compacted
(vermicular) graphite cast irons.
In the case of samples cut from the casting, the letter C is added at the end of the designation by symbol.
In the case of test pieces prepared from separately cast samples, the letter “S” is added at the end of the
grade designation. In the case of test pieces prepared from side-by-side or cast-on samples, the letter
“U” is added at the end of the grade designation.
NOTE The comparison of EN 16079 grade designations with the grades from the ISO standard for compacted
(vermicular) cast irons, ISO 16112:2017 [3], is given in Annex E.
5 Order information
The following information shall be supplied by the purchaser:
a) the number of this European standard;
b) the designation of the material;
c) the relevant wall thickness;
d) mechanical properties and their values (7.4);
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e) the type and size of cast samples, based on relevant wall thickness and load case from design (7.4).
If samples cut from a casting are required, the location(s) of sampling in the casting;
f) the location of sampling for metallographic investigation (7.6);
g) any special requirements.
All requirements shall be agreed between the manufacturer and the purchaser by the time of
acceptance of the order e.g. technical delivery conditions according to EN 1559-1 and EN 1559-3.
6 Manufacture
The method of manufacture of compacted (vermicular) graphite cast irons and its chemical composition
shall be left to the discretion of the manufacturer. The manufacturer shall ensure that the requirements
are met for the material grade specified in the order.
When compacted (vermicular) graphite cast irons are to be used for special applications, the chemical
composition and heat treatment can be agreed upon between the manufacturer and the purchaser.
7 Requirements
7.1 General
The property values apply to compacted (vermicular) graphite cast irons cast in sand moulds or moulds
of comparable thermal behaviour. Subject to an agreement between the manufacturer and the
purchaser, castings can be obtained by alternative methods.
The material designation is based on the minimum mechanical properties obtained in cast samples with
a thickness or diameter of 25 mm. The designation is irrespective of the type of cast sample.
Mechanical properties are wall thickness dependent as shown in Table 1.
NOTE Tensile testing requires sound test pieces in order to guarantee pure uni-axial stress during the test.
7.2 Test pieces machined from separately cast samples
The minimum tensile properties of compacted (vermicular) graphite cast iron, determined using test
pieces machined from separately cast samples according to Figure 1 and Figure 2 shall be as specified in
Table 1.
7.3 Test pieces machined from side-by-side and cast-on samples
The minimum tensile properties of compacted (vermicular) graphite cast iron, determined using test
pieces machined from side-by-side cast samples according to Figure 1, Figure 2 or Figure 3 or to cast-on
samples according to Figure 4, shall be as specified in Table 1.
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Table 1 — Mechanical properties measured on test pieces machined from separately cast, cast
side-by-side or cast-on samples
Relevant wall 0,2 % proof Tensile
Elongation
thickness strength strength
Material designation
R R
t A
p0,2 m
mm MPa MPa %
Symbol Number min. min. min.
12,5 < t ≤ 30 210 300 2,0
EN-GJV-300 5.2100 30 < t ≤ 60 195 275 2,0
60 < t ≤ 200 175 250 2,0
12,5 < t ≤ 30 245 350 1,5
EN-GJV-350 5.2200 30 < t ≤ 60 230 325 1,5
60 < t ≤ 200 210 300 1,5
12,5 < t ≤ 30 280 400 1,0
EN-GJV-400 5.2201 30 < t ≤ 60 260 375 1,0
60 < t ≤ 200 230 325 1,0
12,5 < t ≤ 30 315 450 1,0
EN-GJV-450 5.2300 30 < t ≤ 60 280 400 1,0
60 < t ≤ 200 260 375 1,0
For relevant wall thicknesses greater than 200 mm, the manufacturer and the purchaser shall agree on the type
and size of the cast sample and the minimum values to be obtained.
NOTE 1 The mechanical properties of test pieces machined from cast-on samples can be different from the
properties of the casting itself, but usually give a better approximation than those obtained from separately cast
samples. Additional values are given in Annex A for guidance.
NOTE 2 The percentage reduction in mechanical properties in thick sections depends upon the casting
geometry and its cooling conditions.
7.4 Test pieces machined from samples cut from a casting
In many cases, Samples obtained directly from the casting better represent the properties of the casting
itself than cast samples. If applicable, the manufacturer and the purchaser shall agree on:
— the location(s) on a casting where the sample(s) shall be taken;
— the mechanical properties that shall be determined;
— the values of these mechanical properties (for information, see Annex C).
NOTE 1 The properties of castings can vary, depending on the complexity of the castings and variation in their
section thickness and cooling rates.
NOTE 2 Mechanical properties for test pieces cut from a casting are affected not only by material properties
(subject of this document) but also by the local casting soundness (not subject of this document).
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7.5 Hardness
Brinell hardness and its range values for the grades listed in Table 1 shall only be specified when agreed
between the manufacturer and the purchaser by the time of acceptance of the order.
Typical Brinell hardness values are given in Annex A, Table A.1 for guidance only.
7.6 Graphite structure
Compacted (vermicular) graphite cast irons shall have predominantly graphite particles in the
vermicular form (form III according to EN ISO 945-1), when viewed on a two-dimensional plane of
polish. A maximum of 20 % of the graphite particles, in sections representative of the relevant wall
thickness, can be of form IV, form V and form VI according to EN ISO 945-1. In compacted (vermicular)
graphite cast irons, particles similar to form V and form VI can be referred to as “intermediate”
particles, as defined in Annex B.
Samples for metallographic examination shall be taken from locations agreed between the
manufacturer and the purchaser by the time of acceptance of the order.
A method for metallographic evaluation of nodularity in compacted (vermicular) graphite cast iron
microstructures by image analysis is given in Annex B. The manufacturer and the purchaser shall agree
on the graphite structure evaluation method.
Flake (lamellar) graphite (form I according to EN ISO 945-1) is not permitted, except within the surface
rim zone of the casting. Flake graphite is therefore not considered in the calculation of nodularity. If
flake graphite is present (except in the surface rim zone), the microstructure shall be rejected and a
nodularity assessment shall not be conducted. The thickness of the surface rim zone shall be agreed
between the manufacturer and the purchaser by the time of acceptance of the order.
Although the conventional definition of compacted (vermicular) graphite cast iron is within the range of
0 % to 20 % nodularity, a separate agreement can be made between the manufacturer and the
purchaser for other nodularity ranges. However, the maximum nodularity shall be not more than 30 %.
The graphite structure shall be confirmed either by metallographic examination or by non-destructive
methods. In case of dispute, the result of the metallographic examination shall prevail.
8 Sampling
8.1 General
Samples shall be made from the same material as that used to produce the casting(s), which they
represent.
Several types of samples (separately cast samples, cast-on samples, side-by-side cast samples or
samples cut from a casting) can be used, depending on the mass and wall thickness of the casting.
When relevant, the type of sample should be agreed between the manufacturer and the purchaser.
Unless otherwise agreed, the choice of option is left to the discretion of the manufacturer.
When the mass of the casting exceeds 2 000 kg and its relevant wall thickness exceeds 60 mm, cast-on
samples or samples cut from a casting should preferably be used. The dimensions and the location of
the sample shall be agreed between the manufacturer and the purchaser by the time of acceptance of
the order.
All samples shall be adequately marked to guarantee full traceability to the castings that they represent.
The samples shall be subject to the same heat treatment as that of the castings they represent, if any.
Tensile test pieces shall be finally machined from the samples after the heat treatment.
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8.2 Cast samples
8.2.1 Size of cast sample
The size of the sample shall be in correspondence with the relevant wall thickness of the casting as
shown in Table 2.
If other sizes are used, this shall be agreed between the manufacturer and purchaser.
Table 2 — Types and size of cast sample and size of tensile test pieces in relation to relevant wall
thickness of the casting
Type of sample
Preferred
Relevant wall
diameter of tensile
Option 1 Option 2 Option 3
Cast-on
thickness
a
test piece
sample
U-shaped Y-shaped Round bar
t (see Figure 1) (see Figure 2) (see Figure 3) (see Figure 4) d
mm mm
b c
t ≤ 12,5 – I A 7 (Option 3: 14 mm)
Types
a b c
12,5 < t ≤ 30 – II B 14
Types
b
30 < t ≤ 60 III – C 14
60 < t ≤ 200 – IV – D 14
a
Other diameters, in accordance with Figure 5, may be agreed between the manufacturer and the purchaser.
b
The cooling rate of this cast sample corresponds to that of a 40 mm thick wall.
8.2.2 Frequency and number of tests
Samples representative of the material shall be produced at a frequency in accordance with the in-
process quality assurance procedures adopted by the manufacturer or as agreed with the purchaser.
In the absence of an in-process quality assurance procedure or any other agreement between the
manufacturer and the purchaser, a minimum of one cast sample for the tensile test shall be produced to
confir
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