SIST EN ISO 3690:2018

SLOVENSKI STANDARD
01-november-2018
1DGRPHãþD
SIST EN ISO 3690:2012
9DUMHQMHLQVRURGQHWHKQLNH'RORþHYDQMHYRGLNDYþLVWLKYDULKSULREORþQHP
YDUMHQMX,62
Welding and allied processes - Determination of hydrogen content in arc weld metal (ISO
3690:2018)
Schweißen und verwandte Prozesse - Bestimmung des Wasserstoffgehaltes im
Lichtbogenschweißgutl (ISO 3690:2018)
Soudage et techniques connexes - Détermination de la teneur en hydrogène dans le
métal fondu pour le soudage à l'arcl (ISO 3690:2018)
Ta slovenski standard je istoveten z: EN ISO 3690:2018
ICS:
25.160.40 Varjeni spoji in vari Welded joints and welds
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

EN ISO 3690
EUROPEAN STANDARD
NORME EUROPÉENNE
September 2018
EUROPÄISCHE NORM
ICS 25.160.40 Supersedes EN ISO 3690:2012
English Version
Welding and allied processes - Determination of hydrogen
content in arc weld metal (ISO 3690:2018)
Soudage et techniques connexes - Détermination de la Schweißen und verwandte Prozesse - Bestimmung des
teneur en hydrogène dans le métal fondu pour le Wasserstoffgehaltes im Lichtbogenschweißgut (ISO
soudage à l'arc (ISO 3690:2018) 3690:2018)
This European Standard was approved by CEN on 4 September 2018.

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. Up-to-date lists and bibliographical references
concerning such national standards may be obtained on application to the CEN-CENELEC Management Centre or to any CEN
member.
This European Standard exists 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, Former Yugoslav Republic of Macedonia, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania,
Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Romania, Serbia, Slovakia, Slovenia, Spain, Sweden, Switzerland,
Turkey and United Kingdom.
EUROPEAN COMMITTEE FOR STANDARDIZATION
COMITÉ EUROPÉEN DE NORMALISATION

EUROPÄISCHES KOMITEE FÜR NORMUNG

CEN-CENELEC Management Centre: Rue de la Science 23, B-1040 Brussels
© 2018 CEN All rights of exploitation in any form and by any means reserved Ref. No. EN ISO 3690:2018 E
worldwide for CEN national Members.

Contents Page
European foreword . 3

European foreword
This document (EN ISO 3690:2018) has been prepared by Technical Committee ISO/TC IIW
"International Institute of Welding" in collaboration with Technical Committee CEN/TC 121 “Welding
and allied processes” the secretariat of which is held by DIN.
This European Standard shall be given the status of a national standard, either by publication of an
identical text or by endorsement, at the latest by March 2019, and conflicting national standards shall
be withdrawn at the latest by March 2019.
Attention is drawn to the possibility that some of the elements of this document may be the subject of
patent rights. CEN shall not be held responsible for identifying any or all such patent rights.
This document supersedes EN ISO 3690:2012.
According to the CEN-CENELEC Internal Regulations, the national standards organizations of the
following countries are bound to implement this European Standard: Austria, Belgium, Bulgaria,
Croatia, Cyprus, Czech Republic, Denmark, Estonia, Finland, Former Yugoslav Republic of Macedonia,
France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta,
Netherlands, Norway, Poland, Portugal, Romania, Serbia, Slovakia, Slovenia, Spain, Sweden, Switzerland,
Turkey and the United Kingdom.
Endorsement notice
The text of ISO 3690:2018 has been approved by CEN as EN ISO 3690:2018 without any modification.

INTERNATIONAL ISO
STANDARD 3690
Fourth edition
2018-07
Welding and allied processes —
Determination of hydrogen content in
arc weld metal
Soudage et techniques connexes — Détermination de la teneur en
hydrogène dans le métal fondu pour le soudage à l'arc
Reference number
ISO 3690:2018(E)
©
ISO 2018
ISO 3690:2018(E)
© ISO 2018
All rights reserved. Unless otherwise specified, or required in the context of its implementation, no part of this publication may
be reproduced or utilized otherwise in any form or by any means, electronic or mechanical, including photocopying, or posting
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below or ISO’s member body in the country of the requester.
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Phone: +41 22 749 01 11
Fax: +41 22 749 09 47
Email: copyright@iso.org
Website: www.iso.org
Published in Switzerland
ii © ISO 2018 – All rights reserved

ISO 3690:2018(E)
Contents Page
Foreword .iv
1 Scope . 1
2 Normative references . 1
3 Terms and definitions . 1
4 Principle . 1
5 Test procedures . 2
5.1 Production of weld specimens . 2
5.1.1 Summary . 2
5.1.2 Welding fixture . 2
5.1.3 Test piece assemblies . 3
5.1.4 Welding and test piece storage . 4
5.1.5 Recording of data . . . 5
5.2 Welding procedures for the production of weld specimens . 5
5.2.1 Summary . 5
5.2.2 Manual metal arc welding . 6
5.2.3 Submerged arc welding . 7
5.2.4 Tubular cored electrode with or without gas shield and wire electrode
with gas shield .10
5.3 Measurement of hydrogen in the test weld .12
5.3.1 General.12
5.3.2 Displacement of mercury method .12
5.3.3 Thermal conductivity detector method .14
5.3.4 Calibration .16
5.3.5 Linearity .17
5.3.6 Calculation and expression of results .17
5.3.7 Reporting of results .18
5.4 Measurement of total hydrogen content in the weld metal — Rapid methods .18
5.5 Rounding procedure.18
Annex A (informative) Recommendations and restrictions in regard to older methods of
measurement using mercury .20
Annex B (informative) Recommendations and restrictions in regard to older methods of
measurement using glycerine .21
Annex C (informative) Accuracy and reproducibility .22
Bibliography .23
ISO 3690:2018(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 (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.o rg/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 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 the following
URL: www. iso. org/iso/foreword. html.
This document was prepared by IIW, International Institute of Welding, Commission II.
Any feedback, question or request for official interpretation related to any aspect of this document
should be directed to IIW via your national standards body. A complete listing of these bodies can be
found at www. iso. org/members. html.
This fourth edition cancels and replaces the third edition (ISO 3690:2012), which has been technically
revised. The main changes compared to the previous edition are as follows:
— an additional specimen size D has been added;
— changes have been made in required diffusion times for high temperature tests, see 5.3.3.4, 5.3.4
and Table 5.
iv © ISO 2018 – All rights reserved

INTERNATIONAL STANDARD ISO 3690:2018(E)
Welding and allied processes — Determination of
hydrogen content in arc weld metal
1 Scope
This document specifies the sampling and analytical procedure for the determination of diffusible
hydrogen in martensitic, bainitic, and ferritic steel weld metal arising from the welding of such steels
using arc welding processes with filler material.
The techniques specified in this document include collection of diffusible hydrogen via displacement of
mercury or collection into a headspace filled with an inert gas such as argon. The amount of hydrogen
collected is determined by measuring the displaced volume in the former and by, for example, thermal
conductivity in the latter.
The temperature for collection of diffusible hydrogen is controlled to avoid thermal activation of non-
diffusible hydrogen.
NOTE Recommendations and restrictions in regard to older methods of measurement using glycerine are
given in Annex B for any comparison work to these older methods.
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 14175, Welding consumables — Gases and gas mixtures for fusion welding and allied processes
ISO/TR 17671-1, Welding — Recommendations for welding of metallic materials — Part 1: General
guidance for arc welding
ISO 80000-1:2009, Quantities and units — Part 1: General
3 Terms and definitions
No terms and definitions are listed in this document.
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 http: //www .electropedia .org/
4 Principle
Filler material is deposited on to a standard test coupon in a manner that ensures control of pertinent
variables to produce a representative specimen for analysis. Subsequent storage and handling of the
specimen is controlled to prevent premature loss of hydrogen. Finally, the specimen is transferred to
a gas collection apparatus (mercury method) or to a suitable vessel filled with an inert gas (thermal
conductivity method) and held for a period of time at a temperature sufficient to quantitatively release
the diffusible hydrogen into an evacuated gas burette or into the inert gas headspace, respectively. The
amount of hydrogen collected is determined by measuring the displaced volume (mercury method) or
by thermal conductivity. Finally, quantification of the mass of deposited metal or volume of fused weld
ISO 3690:2018(E)
metal enables calculations of diffusible hydrogen in deposited metal, H , or diffusible hydrogen in fused
D
weld metal, H , to be made.
F
NOTE Annex C gives information on determination of accuracy of results when a method other than
displacement of mercury or thermal conductivity detection is used for diffusible hydrogen analysis.
5 Test procedures
5.1 Production of weld specimens
5.1.1 Summary
The welding consumable to be tested is used to deposit a single weld bead, which is rapidly quenched
and subsequently stored at −78 °C or lower until analysis. Cleaning and slag removal are performed on
the chilled specimen.
5.1.2 Welding fixture
An example of a suitable welding fixture to provide uniform test pieces for the welding processes
specified in 5.2 is shown in Figure 1. It is designed to hold the uniform test pieces securely in alignment
during welding and, in particular, to ensure that unclamping upon completion of welding can be carried
out in a single operation according to the conditions specified in 5.1.4 c). The surface temperature of the
fixture shall be between ambient and 25 °C above ambient at the start of each test weld. The fixture may
be water-cooled to decrease the cycle time. The temperature of the cooling water shall be controlled to
prevent condensation of water on the surface of the fixture between test welds.
For all welding processes, the test piece assembly is clamped in the welding fixture using annealed
copper foil as shown in Figure 1. The foil may be annealed repeatedly and quenched in water after each
annealing. Oxide scale after annealing is removed by pickling with dilute nitric acid (10 % by volume)
followed by washing with distilled water and drying.
2 © ISO 2018 – All rights reserved

ISO 3690:2018(E)
Dimensions in millimetres
Key
1 test piece assembly per Figure 2
2 water cooling jacket (if necessary)
3 lever clamp
4 copper foil inserts (1 mm × 15 mm minimum × 300 mm)
A copper
B carbon steel
Figure 1 — Example of a suitable welding fixture and test piece assembly for weld deposits
5.1.3 Test piece assemblies
The test piece assembly shall be prepared from plain carbon non rimming steel with a carbon content
of not more than 0,18 % by mass and a sulfur content of not more than 0,02 % by mass. The assembly
shall conform to the dimensions shown in Figure 2 and Table 1 for assembly A, assembly B, assembly
C, or assembly D with a tolerance of ±0,25 mm on all dimensions except the length of the run on and
run off pieces. The lengths shown in Figure 2 and Table 1 for the run on and the run off piece represent
minimum values.
ISO 3690:2018(E)
All surfaces shall be finished at right angles to ensure good contact between adjacent pieces during the
welding operation. Each test piece assembly may be finished with one operation on a surface grinder so
as to ensure a uniform width, or closer dimensional control may be exercised to obtain proper clamping.
See 5.1.4 d) for evidence of proper clamping.
The centre test piece shall be numbered by engraving or stamping on the opposite side of that used for
welding. The entire test piece assembly shall be degassed at 650 °C ± 10 °C for 1 h and cooled in either
a dry inert gas atmosphere or a vacuum. Alternatively, the test piece assembly may be degassed and
cooled in air if the surface oxide layer is removed prior to testing. Degassed test piece assemblies shall
be stored in a desiccator or under other suitable conditions to prevent oxidation of the test pieces. After
numbering and removal of oxide, the mass, m , of each centre test piece shall be determined to the
nearest 0,1 g for assembly A or to the nearest 0,01 g for assembly B, assembly C, or assembly D.
Key
a run on piece of length l
a
b run off piece of length l
b
c centre test piece of length l
c
e test piece width
t test piece thickness
Figure 2 — Dimensions of the weld test assembly
Table 1 — Dimensions of the weld test assembly
Dimensions in millimetres
Test assembly l and l l e t
a b c
a
A ≥25 (50) 80 25 12
B ≥25 (50) 30 15 10
C ≥50 15 30 10
D ≥25 (50) 40 25 12
l ≥ 25 mm and l ≥ 25 mm: manual metal arc welding
a b
l ≥ 50 mm and l ≥ 50 mm: other welding processes
a b
a
Identical to the specimen geometry according to AWS A4.3-93.
5.1.4 Welding and test piece storage
The temperature of the welding fixture before each weld is made shall be ambient or not more than
25 °C above ambient. If difficulty is caused by condensation of water on the fixture and test piece
assembly, it is necessary to use cooling water thermostatically controlled to ambient temperature or as
much as 25 °C higher. Using the welding process as specified in 5.2, and parameters appropriate to the
type of investigation, a single weld bead shall be made on the test piece assembly that is clamped in the
welding fixture as shown in Figure 1.
4 © ISO 2018 – All rights reserved

ISO 3690:2018(E)
The test piece assembly shall be cleaned in acetone prior to being clamped into the welding fixture.
Copper foil strips, as shown in Figure 1, shall be used to facilitate thermal transfer and prevent erosion
of the fixture.
The welding procedure is specified in steps a) to f):
a) Welding shall be initiated on the run on piece at a point sufficiently distant from the centre test piece
such that a stable arc and a stable deposit shape are achieved before reaching the centre test piece.
b) Welding shall be terminated when the trailing edge of the crater is on the run off piece but shall not
exceed a distance of 25 mm from the centre test piece.
c) After extinction of the arc, the clamp shall be released and the test piece assembly removed and
immersed at 4 s ± 1 s in an ice water bath. The test piece assembly shall be vigorously agitated
or stirred in the ice water bath. After 20 s ± 2 s, the test piece assembly shall be transferred as
quickly as possible and completely immersed in a low temperature bath containing, for example,
methanol and solid carbon dioxide, denatured alcohol and solid carbon dioxide or liquid nitrogen.
After removal of the specimen from the ice water, ice shall still be present in the bath.
d) After a minimum of 2 min, the test assembly may be removed from the low temperature bath for
cleaning and inspection. All slag and welding fume residue shall be removed by steel wire brushing.
The run on and run off pieces shall be broken off from the centre test piece. The underside of this
piece shall be examined to assess the uniformity and extent of heat tinting. Properly aligned and
clamped test assemblies shall show parallel and uniform heat tinting of the underside of the centre
test piece. Dark oxidation shall not extend to the edges of the underside of the centre test piece. If
this entire operation is not completed within 60 s, the centre test piece shall be returned to the low
temperature bath for a minimum of 2 min before completing these steps.
e) Centre test pieces may be stored at −78 °C or lower in a methanol and solid carbon dioxide or
denatured alcohol and solid carbon dioxide bath for a period of up to 72 h or at −196 °C in liquid
nitrogen for a period of up to 21 days before analysis.
f) For purposes of classifying welding consumables, during welding of the test assembly, the ambient
absolute humidity shall be at least 3 g of water vapour per 1 000 g of dry air. (This corresponds to
20 °C and 20 % relative humidity.) When the relative humidity, measured using a sling hygrometer
or other calibrated device, equals or exceeds this condition, the test shall be acceptable as
demonstrating compliance with the requirements of this document provided the actual test results
satisfy the diffusible hydrogen requirements of the applicable consumable classification standard.
(The measurement of relative humidity can be easily converted to absolute humidity and reported
as such.)
5.1.5 Recording of data
All relevant welding data, as shown on the data sheets, shall be recorded on the appropriate weld data
sheet. Reference should be made to the suggested report forms for each welding process data sheet (see
Tables 2, 3, and 4). Ambient conditions of temperature and humidity at the time of welding shall also be
recorded and absolute humidity reported with the analytical results.
5.2 Welding procedures for the production of weld specimens
5.2.1 Summary
The operating parameters of the welding process under investigation shall be defined to produce a
single weld bead on a test piece assembly as specified in 5.1. See 5.2.2 to 5.2.4 for specifications of the
procedures for different welding processes.
ISO 3690:2018(E)
5.2.2 Manual metal arc welding
5.2.2.1 Electrodes
The covered electrode to be tested shall be used in one of the ways a) or b).
a) For purposes of classification, the electrode and the method of deposition of the weld shall be as
specified in the standard with which the electrode complies.
b) For purposes of investigation, the electrode and welding parameters shall be those given in the
specific welding procedure. If no procedure has been given, then a current that is 90 % of the
maximum suggested by the manufacturer shall be used.
When a pre-drying treatment is required, the time and temperature specified by the consumable
manufacturer shall be used. If a range is given by the manufacturer, e.g. 300 °C to 350 °C, then the
average shall be used and reported.
Electrodes with cracked or broken coatings shall not be used. Electrodes to be tested in the as received
condition shall be taken from a freshly opened undamaged package. During any drying treatment, the
electrodes shall not touch each other or the side of the oven. During any drying operation, a calibrated
oven shall be used and the electrodes shall spend the full specified time at the drying temperature.
Only electrodes under test shall be placed in the oven during this time. When the drying operation is
complete, the electrode shall be cooled to ambient temperature in a container, e.g. a dried borosilicate
glass tube sealed with a rubber bung. The electrode shall be used as soon as possible after it reaches
ambient temperature, but not more than 1 h after removal from the oven unless securely sealed. Any
electrodes removed from the drying oven and not then used shall not be re-dried and subsequently
used for the test.
When electrodes are to be tested in the as received condition from a hermetically sealed container,
the electrodes shall be protected from moisture pickup once the seal is broken, until each can be
welded. Some sealed containers are re-sealable. In such a case, each test electrode can be withdrawn
individually and the container resealed while the withdrawn electrode is welded. If the container is
not re-sealable, then all of the test electrodes shall be withdrawn when the seal is broken, and each
electrode shall be individually placed in a dried borosilicate glass tube sealed with a rubber bung until
the electrode is to be used for test.
5.2.2.2 Making the test welds
A copper fixture, such as that shown in Figure 1, shall be used for the alignment and clamping of the
test piece assembly. The fixture may incorporate water cooling channels in order to achieve a faster
throughput of test pieces. Either test piece assembly A, assembly B, or assembly D may be used.
If the classification standard is silent on this matter, the following shall apply. The classification of
covered electrodes is carried out using 4 mm diameter electrodes. In this case, the welding current shall
be 15 A less than the maximum or 90 % of the maximum stated by the manufacturer, being maintained
within a tolerance of ±10 A. For an electrode with a diameter of 4 mm, the speed of welding shall be
adjusted to produce an 8 g minimum weld deposit on the centre test piece of assembly A, a 3 g minimum
weld deposit on the centre test piece of assembly B, or a 4 g minimum weld deposit on the centre test
piece of assembly D, which is usually accomplished with an electrode consumption of between 1,2 cm
and 1,3 cm per centimetre of weld. Record welding parameters and calculate heat input in accordance
with ISO/TR 17671-1. For all consumable diameters other than the 4 mm specified above, the weld
deposit sample mass shall be representative of good welding practice and appropriate for the diameter
and process applied; no minimum weld deposit sample mass is specified.
Three or more test welds shall be made on three or more test piece assemblies using a new electrode for
each weld. The deposit shall be made, without weaving, along the centre line of the test piece assembly,
as shown in Figure 1. The lengths of the run on and the run off pieces shall be 25 mm minimum. No
burning off prior to testing shall be allowed. The run on deposit length shall not exceed 25 mm. The
time spent in deposition shall be noted. Welding shall be terminated when the trailing edge of the crater
is on the run off piece, but shall not exceed a distance of 25 mm from the centre test piece.
6 © ISO 2018 – All rights reserved

ISO 3690:2018(E)
The method of using the welding fixture is specified in 5.1.4. When welding is completed, the weld
specimen shall be quenched and stored as specified in 5.1.4, after which it shall be cleaned and analysed
for hydrogen content as specified in 5.3.
At the time of welding, due to the influence of atmospheric moisture on the test results, for purposes of
classifying covered electrodes, the arc length shall be maintained as short as possible consistent with
maintaining a steady arc. For all purposes, the details listed in 5.2.2.3 shall be recorded.
5.2.2.3 Recording of welding data and results report form
The report sheet given in Table 2 provides full details of all the test variables that pertain to the test
results.
5.2.3 Submerged arc welding
5.2.3.1 Electrode wire
The consumable solid or cored wire to be tested shall be used in one of the ways a) or b).
a) For purposes of classification, the welding parameters shall be the same as those used in the
preparation of the all weld metal test assembly for mechanical property determination using
4 mm electrode wire, with travel speed adjusted to provide a deposit mass on the centre test
piece of 8 g minimum (assembly A), 3 g minimum for the smaller centre test piece (assembly C),
or 4 g minimum for the smaller centre test piece (assembly D), unless otherwise specified in the
classification document. Test piece assembly B is not acceptable for submerged arc welds. For all
consumable diameters other than the 4 mm specified above, the weld deposit sample mass shall be
representative of good welding practice and appropriate for the diameter and process applied; no
minimum weld deposit sample mass is specified.
b) For purposes of investigation, the electrode wire and welding parameters shall be those given in
the specific welding procedure. The use of a solid wire that has been degassed in a vacuum or inert
gas at 650 °C for 1 h facilitates the investigation of the effect of welding parameters, and type of
flux and its drying procedure, upon the hydrogen content of the weld.
The arc energy for making the weld is restricted to a maximum of 3 kJ/mm.
5.2.3.2 Flux
When drying is required, the flux shall be dried in one of the ways a) or b).
a) For purposes of classification, drying shall be done in accordance with the requirements of the
standard with which the flux complies. Any preconditioning or drying of the flux shall be reported
when an “H” designator is affixed to the flux classification.
b) For purposes of investigation, drying shall be done in accordance with the appropriate
recommendations.
Approximately 1 kg of flux is required for three welds. Drying shall be done in an open container placed
in a calibrated drying oven set at the correct temperature. Flux depth should be limited in order to
ensure that the entire mass of flux reaches the required temperature.
The flux shall spend the full specified time at the drying temperature and no other item(s) shall be
placed in the oven during this time. When the drying treatment is complete, the flux shall be cooled to
ambient temperature and used immediately. Alternatively, the flux shall be cooled in a sealed container
and stored until required for use. Used flux shall not be recycled.
ISO 3690:2018(E)
Table 2 — Report form (diffusible hydrogen, manual metal arc)
Investigating laboratory: Date:
Investigator's name:
Brand name & electrode maker: Batch No.:
Type of electrode: Electrode designation:
Diameter of electrode (mm): Overall length of electrode (mm):
Drying treatment:____ °C for ____ h
Electrode polarity (d.c. +ve, d.c. −ve or a.c.):
Relative humidity ____ % and temperature ____ °C at the welding station during welding
Hydrogen extraction temperature: ____ °C
Hydrogen extraction time: ____ days ____ h ____ min
Type of test piece assembly (A or B or D):
Number of test piece: 1 2 3
Voltage, V; a.c. or d.c.:
Current, A:
Welding time, s:
Weld length, mm:
Heat input, kJ/mm:
Electrode length used, mm:
Run-on length, mm:
Mass of deposited metal on test piece, g:
Test piece to crater distance, mm:
Diffusible hydrogen
1 2 3 Average
a)  H , ml/100 g of deposited metal:
D
b)  H , ppm of fused metal:
F
Other test details not included above:

5.2.3.3 Making the test welds
A copper fixture, such as that shown in Figure 1, shall be used for the alignment and clamping of the
test piece assembly. The fixture may incorporate water cooling channels in order to achieve a faster
throughput of test pieces. Either test piece assembly A, assembly C, or assembly D may be used.
The centre piece remains the same size as specified in 5.1.3, but is aligned with longer run on and
run off pieces of 50 mm minimum. The preparation, degassing, and use of the test piece assembly are
specified in 5.1.3. The flux is kept at a predetermined constant depth of 25 mm or as recommended by
the manufacturer. One method of controlling flux depth is by levelling off along the top of the copper
foil inserts shown in Figure 3. The flux depth of 25 mm or a different flux depth specified by the flux
manufacturer, determines whether the dimension of the copper foil should be modified in order to
achieve the specified flux depth. At the end of the copper foil, there shall be a suitable piece of copper
foil to contain the flux.
Three or more test welds shall be made on different test piece assemblies. The deposit shall be along
the centre line of the test piece assembly. The time spent in deposition shall be noted. The trailing end
of the crater shall be entirely on the run off piece, but no further than 25 mm from the centre test piece
for submerged arc welding. No length for the run on portion of the weld deposit is specified, but the
length shall be sufficient to achieve arc and deposit stability before reaching the centre test piece.
8 © ISO 2018 – All rights reserved

ISO 3690:2018(E)
After extinction of the arc, and without any delay, the test piece assembly shall be released from the
fixture and the test piece quenched, cleaned, and stored as specified in 5.1.4.
Key
1 1 mm copper foil, of dimensions 35 mm ⨯ 300 mm or 37 mm ⨯ 300 mm (for flux depth of 25 mm)
2 test piece assembly
3 welding fixture
Figure 3 — Example of the use of copper foil to maintain constant flux depth
5.2.3.4 Recording of welding data and results report form
The report sheet given in Table 3 provides full details of all the test variables that pertain to the test
results.
Table 3 — Report form (diffusible hydrogen, submerged arc)
Investigating laboratory: Date:
Investigator's name:
Electrode diameter, mm: Electrode designation:
Flux designation:
Brand name & electrode maker: Batch No.:
Brand name & flux maker: Batch No.:
Flux drying temperature and time: ____ °C for ____ h
Electrode polarity (d.c. +ve, d.c. −ve or a.c.):
Relative humidity ____ % and temperature ____ °C at the welding station during welding
Hydrogen extraction temperature: ____ °C
Hydrogen extraction time: ____ days ____ h ____ min
Type of test piece assembly (A or C or D):
Number of test piece: 1 2 3
Voltage, V; a.c. or d.c.:
Current, A:
Welding time, s:
Weld length, mm:
Welding speed, mm/s:
Heat input, kJ/mm:
Wire feed speed, mm/s:
Contact tube distance, mm:
ISO 3690:2018(E)
Table 3 (continued)
Run-on length, mm:
Mass of deposited metal on test piece, g:
Test piece to crater distance, mm:
Diffusible hydrogen
1 2 3 Average
a)  H , ml/100 g of deposited metal:
D
b)  H , ppm of fused metal:
F
Other test details not included above:

5.2.4 Tubular cored electrode with or without gas shield and wire electrode with gas shield
5.2.4.1 Filler material
The filler material to be tested shall be used in one of the ways a) or b).
a) For purposes of classification, the welding parameters shall be the same as those used in the
preparation of the all weld metal test assembly for mechanical property determination using a
1,2 mm wire electrode, with travel speed adjusted to obtain a weld deposit mass on the centre test
piece of 8 g minimum (assembly A), 3 g minimum for the smaller centre test piece (assembly B),
or 4 g minimum for the smaller centre test piece (assembly D), unless otherwise specified in the
classification document. It is well established that diffusible hydrogen results from tubular cored
electrodes are strongly affected by the electrode extension. Care shall be taken that the contact
tip to work distance used for the diffusible hydrogen test is the same as that used in preparing the
all weld metal test coupon for mechanical property determination. For all consumable diameters
other than the 1,2 mm specified above, the weld deposit sample mass shall be representative of
good welding practice and appropriate for the diameter and process applied; no minimum weld
deposit sample mass is specified.
b) For investigation purposes, the filler material and welding parameters shall be those given in the
appropriate welding procedure. If a current range is given by the manufacturer, then the average
shall be used.
5.2.4.2 Shielding gas
The shielding gas shall be of a welding grade as specified in ISO 14175. The shielding gas used and
gas flow shall be in accordance with the appropriate recommendations. Details of the shielding gas
composition and flow shall be recorded on the report form. For investigation purposes, it may
sometimes be necessary to dry the shielding gas in order to remove moisture. If this is done, then the
moisture content of the gas shall be measured and reported.
5.2.4.3 Making the test welds
A copper fixture such as that shown in Figure 1, shall be used for the alignment and clamping of the
test piece assembly. The fixture may incorporate water cooling channels in order to achieve a faster
throughput of test pieces. Either test piece assembly A, assembly B, or assembly D may be used.
The run-on and run-off pieces of the test piece assemblies shall have a minimum length of 50 mm. The
test piece assembly shall be clamped in the fixture using annealed copper foil as shown in Figure 1.
Three or more test welds shall be made on different test piece assemblies. The deposit shall be along
the centre line of the test piece assembly and weld deposit masses shall be as specified in 5.2.4.1. The
time spent in deposition shall be noted. The trailing end of the crater shall be on the run off piece, but
at a maximum distance of 25 mm from the centre test piece. No length for the run on portion of the
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ISO 3690:2018(E)
weld deposit is specified, but the length shall be sufficient to achieve arc and deposit stability before
reaching the centre test piece.
After extinction of the arc and without any delay, the test piece assembly shall be released from the
fixture and the test piece quenched, cleaned, and stored as specified in 5.1.4.
5.2.4.4 Recording of welding data and results report form
The report sheet given in Table 4 provides full details of all the test variables that pertain to the test
results.
Table 4 — Report form (diffusible hydrogen, MIG, MAG, TIG or cored electrode)
Investigating laboratory: Date:
Investigator's name:
Type of filler material: Drying treatment: ____ °C for ____ h
Filler material designation: Gas cup i.d., mm:
Brand name and electrode maker: Batch No.: Diameter of filler material, mm:
Shielding gas:
Shielding gas flow, l/min:
Electrode polarity (d.c. +ve, d.c. −ve or a.c.): Details of tungsten electrode, if any :
Make:
Relative humidity ____ % and temperature ____°C at Diameter, mm:
the welding station during welding
Hydrogen extraction temperature: ____ °C Cone angle:
Hydrogen extraction time: ____ days ____ h ____ min Designation
Type of test piece assembly (A or B or D):
Number of test piece: 1 2 3
Voltage, V; a.c. or d.c.:
Current, A:
Welding time, s:
Weld length, mm:
Welding speed, mm/s:
Heat input, kJ/mm:
Wire feed speed, mm/s:
Contact tube distance, mm:
Run-on length, mm:
Mass of deposited metal on test piece, g:
Test piece to crater distance, mm:
Diffusible hydrogen
1 2 3 Average
a)  H , ml/100 g of deposited metal:
D
b)  H , ppm of fused metal:
F
Other test details not included above:

ISO 3690:2018(E)
5.3 Measurement of hydrogen in the test weld
5.3.1 General
The measurement method shall ensure that only diffusible hydrogen is released from the test specimen
and is collected, and material dependent activation of potential trapped hydrogen sources shall be
avoided. Two methods of diffusible hydrogen analysis are specified in this document, displacement of
mercury and thermal conductivity detection.
NOTE Recommendations and restrictions in regard to older methods of measurement using mercury are
given in Annex A.
5.3.2 Displacement of mercury method
The gas collection apparatus specified in this clause is known as a Y tube and mercury shall be used
as the collecting fluid. Other designs of collecting may be used, provided the same principles as for the
Y tube are used. The gas collection apparatus s
...