GOST R ISO 17642-2-2012

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  ГОСТ Р ИСО 17642-2-2012

GOST R ISO 17642−2-2012 destructive Testing of welds of metallic materials. Tests on resistance to formation of cold cracks in welded joints. The arc welding processes. Part 2. Tests with the natural stiffness

GOST R ISO 17642−2-2012

Group B09

NATIONAL STANDARD OF THE RUSSIAN FEDERATION

DESTRUCTIVE TESTING OF WELDED JOINTS OF METALLIC MATERIALS

Tests on resistance to formation of cold cracks in welded joints. The arc welding processes

Part 2

Tests with the natural stiffness

Destructive tests on welds in metallic materials. Cold cracking tests for weldments. Arc welding processes. Part 2. Self-restraint tests

OKS 25.160.40

Date of introduction 2014−01−01

Preface

1 PREPARED by the Federal state institution «Scientific-educational center «welding and control» at MGTU im.N. Uh. Bauman (FGU «NORSK» at MSTU.N. Uh. Bauman) and the National Agency for control and welding (NAKS) on the basis of their own authentic translation into the Russian language of the international standard indicated in paragraph 4

2 SUBMITTED by the Technical Committee for standardization TC 364 «welding and allied processes"

3 APPROVED AND put INTO EFFECT by the Federal Agency for technical regulation and Metrology, dated 22 November 2012 N 1010-St

4 this standard is identical to international standard ISO 17642−2:2005* «Destructive testing of welds of metallic materials. Tests on resistance to formation of cold cracks in welded joints. The arc welding processes. Part 2. Tests with the natural rigidity» (ISO 17642−2:2005 «Destructive tests on welds in metallic materials — Cold cracking tests for weldments — Arc welding processes — Part 2: Self-restraint tests»).
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* Access to international and foreign documents referred to here and hereinafter, can be obtained by clicking on the link to the site shop.cntd.ru. — Note the manufacturer’s database.

In applying this standard it is recommended to use instead of the referenced international standards corresponding national standards, the details of which are given in Appendix YES

5 INTRODUCED FOR THE FIRST TIME


Application rules of this standard are established in GOST R 1.0−2012 (section 8). Information about the changes to this standard is published in the annual (as of January 1 of the current year) reference index «National standards» and the official text changes and amendments — in monthly information index «National standards». In case of revision (replacement) or cancellation of this standard a notification will be published in the upcoming issue of the monthly information index «National standards». Relevant information, notification and lyrics are also posted in the information system of General use — on the official website of the Federal Agency for technical regulation and Metrology on the Internet (gost.ru)

Introduction

ISO 17642−2 by the European Committee for standardization (CEN) in collaboration with technical Committee ISO/TC 44 «welding and allied processes», Subcommittee SC 5 «Testing and inspection of welds» in accordance with the Agreement on technical cooperation between ISO and SEN (Vienna Agreement).

ISO 17642 consists of the following parts, under the General name of «destructive Testing of welds of metallic materials. Tests on resistance to formation of cold cracks in welded joints. The arc welding processes» and includes:

part 1. General provisions;

part 2. Tests with the natural stiffness;

part 3. Tests with the application of an external load.

Annex ZA contains the list of the relevant international and European standards, which equivalents are not given in the text.

1 Scope

This standard establishes requirements for samples and procedures that should be performed when testing for resistance to formation of cold cracks in welded joints of the samples with the natural stiffness by:

— CTS-test (under controlled thermal rigidity);

— Tekken-test (with Y-shaped cut) or Lehigh-test (if the U-shaped cutting).

The test is performed for information on resistance to formation of cold cracks during welding.

This standard applies primarily, but not exclusively, for manganese and low alloy steels.

2 Normative references

This standard uses the regulatory references to the following international standards*. Subsequent amendments or modifications are valid for dated references of this standard only after the introduction of amendments and changes to it. For undated references the latest applicable edition of the referenced document (including amendments thereto).
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* The table of conformity of national standards international see the link. — Note the manufacturer’s database.

YONG 1043−1:1995 Destructive tests of welds metallic materials — hardness Measurement — Part 1: hardness testing of joints made with arc welding(EN 1043−1:1995, Destructive tests on welds in metallic materials — Hardness testing — Part 1: Hardness test on arc welded joints)
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Replaced by EH ISO 9015−1:2011.

EH 1321 Destructive tests of the welded joints in metallic materials — Macroscopic and microscopic examination of welds (EN 1321, Destructive tests on welds in metallic materials — Macroscopic and microscopic examination of welds)

EH ISO 3690 welding and allied processes — Determination of hydrogen content in the weld metal with the ferritic structure is made arc welding (ISO 3690:2000) (EN ISO 3690, Welding and allied processes — Determination of hydrogen content in ferritic arc weld metal (ISO 3690:2000)

EH ISO 17642−1:2004 Destructive tests of welds metallic materials — Testing of welded joints on cold cracking — arc welding Processes — Part 1: General (ISO 17642−1:2004) (EN ISO 17642−1:2004, Destructive tests on welds in metallic materials — Cold cracking tests for weldments — Are welding processes — Part 1: General (ISO 17642−1:2004))

3 Terms and definitions

This standard applies the terminology and definitions given in EN ISO 17642−1:2004.

4 Indicators and symbols

Apply indicators and symbols are given in table 1.


Table 1 — Indicators and signs

5 Fundamental provisions

5.1 General provisions

Tests on resistance to formation of cold cracks in welded joints of the samples with the natural rigidity designed to assess the resilience of the basic and welding materials cold cracking.

The test consists of the execution of the weld on the test sample of the two plates according to pre-existing conditions and verification of cross-sections of welded joints to detect possible cracks in the weld metal and the heat affected zone.

This procedure applies mainly in arc welding with covered electrodes and semi-automatic welding in protective gas with solid and flux cored wire. Typically, this method is not used for processes characterized by large values of welding current, such as arc welding under flux.

5.2 Qualitative assessment

When applying a strict set of conditions of welding of a given material is carried out one assessment test. In the case of the CTS-tests check two subjects of the joint.

5.3 Quantitative evaluation

To establish the boundaries of cracking needs to be performed a series of tests. The test, which does not have any cracks, I repeat, otherwise, should be made other tests.

6 Test

6.1 CTS-test

6.1.1 Dimensions of control samples

The dimensions of the control specimens shall conform to figure 1.

Figure 1 — CTS-test

1 — hole with a diameter of 13 mm; 2 — upper plate; 3 — gap in the root cutout; 4 — bottom plate; 5 — depth of root cut; 6 — preferred direction of rolling; 7 — test joints; 8 — retaining sutures

Figure 1 — CTS-test

6.1.2 Preparation of control samples

All control samples must be made from basic materials which will be welded to be tested welding consumables (see figure 2).

Figure 2 — Device used for positioning of the test node

1 — device for testing; 2 — welding material

Figure 2 — Device used for positioning of the test node

Material samples processed by sawing, milling or grinding. The welding surfaces shall be milled or polished. The processing should minimize heat and deformation.

For control sample, is shown in figure 1 using a normal fixture. Sizes, permissible deviations and other requirements to control samples are shown in table 2.


Table 2 — Dimensions, permissible deviations and other requirements to control samples

The upper and lower plates have the same thickness and to be of the same material. The top plate needs to be machined, the lower can be cut by gas cutting.

In exceptional circumstances when it is impossible to make both plates of the test material, the upper plate is made of the test material, the material equivalent for yield strength. It is important that the sensitivity to crack initiation in the heat affected zone under the influence of hydrogen on the lower plate was smaller than that of the material being tested.

If it is possible to define the main direction of the rolling material, upper and lower plate should be positioned so that the direction of rolling them was equal (see figure 1).

It should be ensured that the welding surfaces were smooth and did not have on the surface of mill scale, rust, oil products, oil and other contaminants.

Plate connecting bolt with a diameter of 12 mm. Bolt, nut and washer before Assembly, degrease. Do not use the bolts and nuts are coated. Using a bolt, nut, washer, plate are tightened with the torque according to table 2. To perform all welding operations check torque and adjust as necessary.

6.1.3 Retaining welds

Retaining sutures (see figure 1) perform the welding materials, the yield strength of which is not less than the yield strength of the material being tested, if it does not exceed 895 N/mm.

Note — If the yield strength of the basic material exceeds 895 N/mm, the welding material may have a yield strength less than that of the base material (but more 895 N/mm) and/or can be used welding of austenitic corrosion-resistant steel.


Start and finish fixing the corner joints at a distance of (10±3) mm from the corners of the upper plate and perform thickness:

To (6±1) mm at plate thickness up to 15 mm;

— (13±1) mm at plate thickness not less than 15 mm.

To prevent hydrogen cracking of welded joints performed by using an optionally pre-heating, heating between welding passes and heating after welding.

To provide the minimum hydrogen content of all welding consumables used to perform the fastening of the seams, dried according to the manufacturer’s recommendations.

Check the torque on the bolt and, if necessary, produce a puff. Before performing subjects suture knot is aged for 12 h

6.1.4 Subjects the welds

6.1.4.1 Pre-heating

If the test sample shall be subjected to preliminary heating, the Assembly is placed in oven and leave for sufficient time to ensure uniform heating. Set the oven temperature above that required for the test subject to the cooling node during the transfer and installation.

Before welding check temperature of tested plates using a calibrated surface pyrometer or thermocouple. If the tests require a certain preheating temperature, welding should not begin to achieve it. The temperature of the upper plates in the test area shall not differ by more than 5 °C.

6.1.4.2 Surfacing

To position the site use a device. The location of the electrode wire relative to the subject site (see figure 2) must be such that the test seams were symmetrical, were situated in the lower position across the width of the plate, were performed in one direction and in one pass. The test seam shall not go beyond the ends of the plate.

The bead length is determined by measuring from the beginning of the seam to the center of the crater, as shown in figure 3. Calculate the value of heat input (kJ/mm).

Note — Manual welding difficult adequate management and supervision. Therefore, it is recommended to use the equipment for mechanized welding.

Figure 3 — Measurement of the length of the seam L

Figure 3 — Measurement of the length of the seam

6.1.4.3 postweld

If provided, the heating after welding, the node is transferred to the furnace immediately after the first test weld. Postweld control calibrated surface pyrometer or a thermocouple.

6.1.4.4 Cooling

After the execution of the first test weld and possible heating after welding, the test node is transferred to a cooling bath so that the side opposite the weld seam, were immersed in flowing water at depths of (60±5) mm (see figure 4).

Figure 4 — location of the control sample in a cooling bath

1 — test seam; 2 — water

Figure 4 — location of the control sample in a cooling bath

Transfer to a bath complete within 60 s after welding (heating after welding, if applicable).

The water temperature at the outlet of the cooling bath should not exceed 30 °C.

The node is kept in the bath until its temperature drops to ambient temperature and then extract it.

6.1.4.5 apply to the Welding of the second weld

After removal of the cooling bath the node kept for at least 48 h before overlaying the second seam test in accordance with 6.2.5.2.

The second subject, the seam is cooled in the same way as the first.

After cooling, the second test of the weld to ambient temperature before proceeding to further work the host stand at least 48 h.

6.1.4.6 the Determination of hydrogen

The content of diffusion hydrogen in the weld material (in ml per 100 g weld metal) determined according to EN ISO 3690 and the relevant standard for welding material.

The atmospheric conditions in determining the content of hydrogen should be a representative available during the test.

6.1.5 test Results

6.1.5.1 Metallographic examination

6.1.5.1.1 Partitioning

Control samples should be divided into samples of equal size for metallographic examination in accordance with the YONG 1321, see figure 5.

Note — do Not apply excessive force, vibration, or methods that cause heat.

Figure 5 — Partitioning CTS control sample

1 — the direction of welding; 2 — surface, which is polished and checked for cracks; 3 — control samples

,  — the surface, which is polished and checked for cracks

Figure 5 — Partitioning CTS control sample

6.1.5.1.2 Preparation and checking

Six surfaces, obtained after cutting, ready to study the microstructure. The prepared surface of the weld metal and heat affected zone are checked for cracks at magnification of at least 50. First check the surface 2b or 3A (see figure 5) in accordance with the YEON-1321. The absence in the samples of cracks is confirmed when a suitable increase of 200.

6.1.5.1.3 Measurement

If the weld metal detect root cracks with a total length of more than 5% of the thickness of the seam, the control sample is considered to be insolvent and study related samples is stopped.

If in the heat affected zone there are cracks with a length of more than 5% of the leg, the test seam are considered «susceptible to cracking» and metallographic examination of stop.

If the cracks are not detected, check all six surfaces.

If the material of the lower plate different from the material of the upper and the cracking is only present in the heat affected zone of the bottom plate, the test is considered invalid.

Figure 6 — Measurement of the length of the leg

The length of the leg .

Figure 6 — Measurement of the length of the leg

6.1.5.1.4 hardness Measurement

One of the main surfaces of each of the test weld (see 3A or 2b in figure 5) measured the Vickers hardness in accordance with YONG 1043−1:1995, figure 4, HV10, HV5.

From the loads of 2.5, 5 and 10 kg are chosen such that in the measurement of hardness could accommodate 10 fingerprints from the coarse-grained heat affected zone. The results on the prints caught in the zone of the weld, fine-grained zone, or not subjected to thermal influence of the primary material is not taken into account and conduct further measurements.

Figure 7 — Typical layout of prints in the measurement of hardness

1 — weld

Note — the Distance of any print to a previously made must be at least permissible according to EN 1043−1.

Figure 7 — Typical layout of prints in the measurement of hardness

6.2 TEKKEN-test (with Y-shaped cut) and Lehigh-test (when the U-shaped cutting)

6.2.1 General provisions

Type Y refers to the more severe conditions of test, and recommended for testing of the base metal. Type U is valid for less stringent test conditions and is recommended for testing of the weld metal.

6.2.2 the Dimensions of the reference samples

The dimensions of the control specimens shall conform to figure 8.

Figure 8A) — tested at the Y-shaped cutting

Figure 8A) — tested at the Y-shaped cutting

Figure 8b) is tested at a U-shaped cutting

Figure 8b) is tested at a U-shaped cutting

 — test area (at Y-shaped or U-shaped cutting);  — the fastening seam; the thickness of the test plates;  — a gap in root of weld, equal to (2,0±0,2) mm;  — diameter holes (depending on the thickness of the plate) and width of cutting

Figure 8. Shape and dimensions of tested plates

6.2.3 Preparation of control samples

Control samples of the test material are cut off with a saw, cutter or sand around. Finish welded surfaces should be milling or grinding. When processing material, you should pay attention to minimize heat and deformation.

General requirements to the control sample is shown in figure 8.

Edge control sample, not subjected to welding, can be able after the gas cutting.

If it is possible to establish the direction of rolling, it should be in both plates are identical and coincide with the direction of welding.

Subject to the welding surface should be smooth, should not have scale, rust, oil, grease and other contaminants.

6.2.4 Fasteners welds

Retaining welds (shown in figure 8 for the sample with Y-shaped cut) is performed with use of the welding material, a yield strength which is not less than the yield strength of the material being tested.

To prevent hydrogen cracking of welded joints performed by using an optionally pre-heating, heating between welding passes and heating after welding.

To provide the minimum hydrogen content of all welding consumables used to perform the fastening of the seams, dried according to the manufacturer’s recommendations.

6.2.5 Subjects the welds

6.2.5.1 Pre-heating

If the test sample shall be subjected to preliminary heating, the Assembly is placed in oven and leave for sufficient time to ensure uniform heating. Set the oven temperature above that required for the test subject to the cooling node during the transfer and installation.

Before welding check temperature of control sample using a calibrated surface pyrometer or thermocouple. If the tests require a certain preheating temperature, welding should not begin to achieve it. Temperature control of the sample in the test area shall not differ by more than 5 °C.

6.2.5.2 welding

Welding is performed in the lower position in the conditions under which the cooling rate has no effect. Welding is started when the temperature of the entire test plate reaches the predetermined preheating temperature.

The test seam is performed, as shown in figure 9a). In automatic welding followed by figures 9b) and 9c). Calculate the value of heat input (kJ/mm).

Notes

1 Preparation of coated electrodes for manual arc welding, put CTS-test sometimes does not meet the manufacturer’s recommendations. Applied in these cases, the methods of treatment indicated in the test report.

2 As manual welding difficult to control the process, it is recommended to use the equipment for mechanized welding.

Figure 9 — Methods of welding of the test weld

Test in Y-shaped cutting

The test at a U-shaped cutting

1 — beginning; 2 — the crater; 3 — subject the weld; 4 — retaining weld; 5 — size of approximately 2 mm; 6 — a size of approximately 76 mm

Figure 9 — Methods of welding of the test weld

6.2.5.3 Heat treatment after welding

If provided, the heating after welding, the node is transferred to the furnace immediately after the first test weld.

Postweld control calibrated surface pyrometer or a thermocouple.

After cooling to ambient temperature, a control sample prior to the production of further works kept for at least 48 h.

6.2.5.4 Determination of hydrogen content

The content of diffusion hydrogen in the weld material (in ml per 100 g weld metal) determined according to EN ISO 3690 and the relevant standard for welding material.

The atmospheric conditions in determining the content of hydrogen should be representative in relation to the terms of the CTS or test for Y-shaped cut.

6.2.6 test Results

6.2.6.1 General provisions

Depending on the requirements of the test seam and check for cracks on the surface, in the root and cross sections of a seam, set their length, calculate the ratio of the cracking and measure the hardness in the heat affected zone.

6.2.6.2 Visual inspection

Visually check the test seam on the presence of surface cracks and calculate the ratio of cracking according to the following formula

,

where  — coefficient of cracking of the root, %;

 — the length of the test joint, mm;

 — the total length of the root cracks, mm.

6.2.6.3 Metallographic examination

6.2.6.3.1 Partitioning

Control samples are divided into sections for metallographic examination in accordance with the YONG 1321 (see figure 11).

Note — do Not apply excessive force, vibration, and practices, causing heating.


If the weld corresponds to figure 9a), five sectionGroup cuts must pass between the ends of the seam and the specified distance is divided into four parts, as shown in figure 11a).

If the weld corresponds to figure 9b), one of the extreme sectionGroup cuts should take place as close as possible to the start of welding where the width of the roller becomes constant, the other as close as possible to the center of the crater of the weld. The distance between the extreme sectioniii cuts is divided into four parts, as shown in figure 11b).

6.2.6.3.2 Preparation and checking

The prepared surface of the weld and heat affected zone are checked for cracks at magnification of at least 50. The conclusion about the absence of cracks in the samples is confirmed when the magnification of at least 200.

6.2.6.3.3 Measurement

The cracking ratio is calculated by the formula

,

where  — coefficient of cracking in the relevant section, %;

 — the minimum thickness of the test weld, mm (see figure 10);

 — height of the root cracks, mm (see figure 10).

Figure 10 — measurement Procedure

Figure 10 — measurement Procedure

Note — Any defects in the weld seam less than 0.5 mm (0.5 mm) in height should not be regarded as cold cracks caused by hydrogen.

Figure 11 — position of the ground check for cracks

1 — cutting in the width direction of the sample; 2 — position check section

Figure 11 — position of the ground check for cracks

6.2.6.4 hardness Measurement

One of the main surfaces of the test weld is measured, the Vickers hardness in accordance with EN 1043−1:1995, figure 6, HV10, HV5.

From the loads of 2.5, 5 and 10 kg are chosen such that in the measurement of hardness could accommodate 10 fingerprints from the coarse-grained heat affected zone. The results on the prints caught in the zone of the weld, fine-grained zone, or not subjected to thermal influence of the primary material is not taken into account and conduct further measurements.

7 Protocol tests (CTS, Y-shaped and U-shaped trim)

The test report should include, if applicable, the following information:

a) designation of this standard;

b) type control sample;

c) identifying a test sample;

d) material of the plates of the control sample;

e) the dimensions of the reference sample;

f) welding conditions and test;

g) the number, position, crack length and microhardness, if applicable;

h) hardness (if applicable);

i) hydrogen.

Examples of typical protocols are given in appendices A and B.

Annex a (informative). The CTS Protocol-testing

Appendix A
(reference)

Annex b (informative). Test in Y-shaped cut (TEKKEN-test) and a U-shaped cut (Lehigh-test)

The App
(reference)

Annex ZA (informative). Normative references to international and relevant European standards

Annex ZA
(reference)

This standard incorporates by dated or undated references, provisions from other publications. Normative references are placed in appropriate places in the text, publications are listed below. For dated references, amendments or modifications of any of these publications apply only if these references are included in the standard by amendment or revision. For undated references, applies the latest revision of this publication (including amendments).

Note — If the international publication has been modified by common modifications, indicated as «mod.», apply relevant EN/HD.

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Replaced by EN ISO 9015−1:2011.

App YES (reference). Information about the compliance of the referenced international standards reference the national standards of the Russian Federation

App YES
(reference)

Table YES.1

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* Probably, the error of the original. Should read: GOST R ISO 17642−1-2011. — Note the manufacturer’s database.

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UDC 621.791.053:006.354 OKS 25.160.40 B09

Key words: welded joints, arc welding, cold cracking, testing
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