GOST R 56143-2014

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  ГОСТ Р 56143-2014

GOST R 56143−2014 (ISO 17642−3:2005) destructive Tests of welded joints of metallic materials. Tests on resistance to formation of cold cracks in welded joints. The arc welding processes. Part 3. Tests with the application of an external load

GOST R 56143−2014
(ISO 17642−3:2005)

NATIONAL STANDARD OF THE RUSSIAN FEDERATION

DESTRUCTIVE TESTING OF WELDED JOINTS OF METALLIC MATERIALS

Tests on resistance to formation of cold cracks in welded connections

The arc welding processes

Part 3

Tests with the application of an external load

Destructive tests on welds in metallic materials. Cold cracking tests for weldments. Arc welding processes. Part 3. Externally loaded tests

OKS 25.160.40

Date of introduction 2016−01−01

Preface

1 DEVELOPED by FSUE «all-Russian research Institute of standardization and certification in engineering» (VNIINMASH) on the basis of their own authentic translation of the standard referred to 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 30 September 2014 N 1242-St

4 this standard is modified in relation to the international standard ISO 17642−3:2005* «Destructive testing of welds of metallic materials. Tests on resistance to formation of cold cracks in welded joints. The arc welding processes. Part 3. Tests with the application of an external load» (ISO 17642−3:2005 «Destructive tests on welds in metallic materials — Cold cracking tests for weldments — Arc welding processes Part 3: Externally loaded tests») by replacing references to international standards that are not adopted as national standards of the Russian Federation, references to the standards in force in the Russian Federation, or the formulation of the requirements of the standard, as well as by eliminating application ZA contains outdated information. The changes are highlighted in italics**.
________________
* 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 the original paper designation and number of standards and normative documents in the sections «Preface», «Introduction» and «Principles» are given in regular font, the other text of the document in italics. — Note the manufacturer’s database.


The introduction of these technical deviations caused by the expedience of the use of force in the Russian Federation standards instead of the referenced international standards

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 17642−3 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»:

— part 1. General provisions;

— part 2. Tests with the natural stiffness;

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

1 Scope

This standard specifies the dimensions of the samples and procedures for the implementation of the implant of tests on resistance to formation of cold cracks in welded joints under the action of external loads.

This standard applies to carbon, manganese and low alloy steels.

2 Normative references

The present standard features references to the following standards.

GOST 2999−75 Metals and alloys. Method of measurement of hardness by Vickers

GOST 23338−91 welding of metals. Methods for the determination of the content of diffusion hydrogen in the deposited metal and the weld metal

GOST R ISO 17642−1-2011 destructive Testing of welds of metallic materials. Tests on resistance to formation of cold cracks in welded joints. The arc welding processes. Part 1. General provisions

Note — When using this standard appropriate to test the effect of reference standards in the information system of General use — on the official website of the Federal Agency for technical regulation and Metrology standardization on the Internet or published annually by the information sign «National standards» published as on January 1 of the current year, and the editions of the monthly information index «National standards» for the current year. If replaced with a reference standard, which was given an undated reference, then it is recommended to use the current version of this standard, taking into account all enabled in this version modifications. If replaced with a reference standard, which is given a dated reference, it is recommended to use the version of this standard referred to above by year of approval (acceptance). If after approval of this standard in the reference standard, which is given a dated reference, a change affecting a provision to which reference, the provision is recommended to be applied without taking into account this change. If the reference standard is cancelled without replacement, the position in which reference is made to him, recommended to be used in part not affecting this link.

3 Terms and definitions

This standard applies the terminology and definitions given in GOST R ISO 17642−1.

4 Indicators and symbols

Applied standard metrics and notation are shown in table 1.

Table 1 — Indicators and signs

5 Principles

The purpose of the test with the application of external loads is to establish the resistance to formation of cold cracks in welded joints. According to table 2 GOST R ISO 17642−1 is no test procedure. When using the cracks in the test samples occur after welding.

Testing can obtain quantitative information about the conditions in which there are no cracks, and qualitative information (no cracks/cracks).

6 description of the tests

6.1 General

6.1.1 a Test of resistance to cold cracking with the application of an external load intended to evaluate the main materials used in arc welding.

This test procedure is used for arc welding with coated electrodes, fully and partially mechanized arc welding with consumable electrode in protective gas with solid and flux cored wire arc and submerged arc welding.

The test provides a qualitative assessment (cracks or no cracks, unit test) and to determine the conditions under which cracks do not exist: the minimum preheat temperature, the lowest heat input, the highest content of diffusion hydrogen or the highest voltage (the definition of the boundary between the presence and absence of cracks).

6.1.2 Unit test

Under given welding conditions, and certain basic material is evaluated only one test.

6.1.3 definition of the boundary between the presence and absence of cracks

If you have a series of tests to identify the boundaries of the conditions leading to the presence/absence of cracks, the test corresponding to the conditions in which cracks form, should be repeated. If during the second test the cracks will also not be present, further testing is not required. If the repeat testing there are cracks, the test was continued until the establishment of the border.

Note 1 — If variable is a linear energy, it is preferable to define the boundary in the interval of ±0.5 kJ/mm and carry out repeated tests through to ±0.1 kJ/mm.

Note 2 — If variable is pre-heating, it is preferable to define the boundary within the interval of ±12,5°C.

6.2 Implant test

6.2.1 Test materials

The implant and plate are made of the same material or materials similar in chemical composition and structure.

6.2.2 Dimensions of samples for testing

The size of the implant and plate shall conform to figures 1, 2, 3 and table 2.

Allowed to use other sizes, indicating this in the test report.

Figure 1 — Implant test

Dimensions in mm

1 — the temperature measuring location; 2 — direction of welding; 3 — implant; 4 — test load F

Note 1 — the Length of the test weld shall be not less than 150 mm.

Note 2 — the distance between the first test seam and the edge of the sheet should be not less than 100 mm.

Figure 1 — Implant test

Figure 2 — Implant screw

Dimensions in mm

Note — the Dimensions M and N depend on the test equipment

Figure 2 — Implant screw

Figure 3 — Implant ring

Figure 3 — Implant ring

6.2.3 Preparation of samples for testing

The implant is made turning, holes in the plate are drilled. Care should be taken to during processing to minimize heat and deformation. Plate size must comply with table 2. The relative position of the plate and the implants should conform to figure 1 and table 2 the permissible deviations table 2.

The implant must be completely covered with the test seam. Typically use an implant with a diameter of 8 mm. When running the small seams use an implant with a diameter of 6 mm.

Table 2 — Parameters of the plate and implants

The hole and the implant should be handled in such a way that the gap between it and the plate ranged from 0.05 mm to 0.15 mm (sliding fit).

6.2.4 welding of test joints

6.2.4.1 Pre-heating

If the test requires pre-heating, the plate and the implant should be preheated by any suitable method. Before welding check temperature of the main plate and the implant using a calibrated thermocouple. If the test requires a certain preheating temperature, welding should not begin until reaching this temperature. The temperature of the plate and the implant in the area of test shall not differ by more than 5 °C.

6.2.4.2 welding

Each weld should be performed in the lower position, in one direction and in one pass. The welding process must be fully or partially mechanized. Welding is not allowed, in which difficult to control and monitor the process.

The penetration should be such that the incision was in the coarse-grained heat-affected zones. Cm. figure 4.

Calculate the value of heat input (kJ/mm).

Note — If you have to perform test welds at the implant test used covered electrodes for manual arc welding, they must be prepared in accordance with the manufacturer’s recommendations for the establishment of a certain hydrogen content, unless tested at different grades.

Figure 4 — Welding of the ring and screw implant

1 — plate;

2 — heat affected zone; 3 — load

Figure 4 — Welding of the ring and screw implant

6.2.4.3 Loading of the implant

The implant is loaded with a tensile static load. The load F is applied after welding at the temperature T, independent of the preheat temperature T.

Given the load to be achieved during the time from 20 to 60 s before the temperature reaches 100 °C or upon reaching its predetermined value.

The sample may be subjected to release not less than 16 hours after loading.

The load F refers to the orthogonal section of the cylinder passing through the base of the incision.

(N/mm) (1)

where is the voltage attributable to the cross-section in the notch;

F — load;

d — diameter implant.

In many cases, is selected equal to the conditional yield strength Rof the material of the implant.

Loading device must meet the following conditions:

— the selected load must be set with an accuracy of ±1% and maintained constant throughout the test;

— the specimen shall not be subjected to bending, torsion or shock.

6.2.4.4 cooling Time in the temperature range t/t

If the implant test do not apply heat after welding, the thermal cycle should be characterized by measuring and recording the time of cooling in the temperature range from 800 °C to 500 °C (t) and cooling time in the temperature range from 300 °C to 100 °C (t).

If after welding apply heat above 100 °C, measure the cooling time in the temperature range t, and the cooling time in the temperature range tis not measured.

The cooling time determines one of the following ways:

— placing the thermocouple in the heat-affected zone of the implant so that the highest recorded temperature was not lower than 1100 °C;

— placing the thermocouple in the metal of the weld to be performed.

Must be a correlation between measurements in the heat affected zone of the implant and in the weld metal. The correlation should be checked periodically.

6.2.4.5 Determination of hydrogen content

The contents in the welding material diffusion of hydrogen (in ml/100 g deposited metal) is determined in accordance with GOST 23338 and standard on welding material.

You should ensure that the atmospheric conditions in determining the content of hydrogen in the weld material representative of atmospheric conditions during the test.

6.2.5 test Results

6.2.5.1 Destruction

The implant can collapse during loading. In this case, the load and time of loading to failure should be recorded.

6.2.5.2 Metallographic examination for cracks

If failure does not occur, cracks that may form around the incision under the action of the applied load, can be detected by conducting metallographic analysis with increase from 400 to 600 times in three longitudinal sections located in the direction of the weld seam, respectively, figure 5.

Figure 5 — Location of the longitudinal sections 1, 2 and 3 for metallographic investigations and hardness measurement

Dimensions in mm

Figure 5 — Location of the longitudinal sections 1, 2 and 3 for metallographic investigations and hardness measurement

6.2.5.3 Study after oxidation cracks

Crack, which could have formed near the incision under the action of applied loads are not identified in the metallographic study, can be detected using the method of oxidation.

The oxidation of hydrogen induced cracks (1 h at temperatures from 250 °C to 300°C) and a fatigue test specimen under the action until the destruction is attached to the implant longitudinal loads occur without separation of the implant from the plate until the sample is destroyed under the action of fatigue. A study of the appearance of failure surface allows to distinguish cold oxidized the crack from further propagation of the fatigue damage.

6.2.5.4 hardness Measurement

The Vickers hardness (HV) heat-affected zone is determined according to GOST 2999 at a load of 98.07 N (10 kgf).

7 test report

The test report must contain the following information:

a) reference to this standard;

b) identification plate/implant;

c) material of plate and implant (chemical composition and mechanical properties);

d) the diameter of the implant;

e) type of incision (screw, ring);

f) welding conditions and the test (welding process, welding material, hydrogen, welding parameters, preheat temperature, voltage);

g) the number, length of cracks and the methods of their detection;

h) time and load to failure or the time of exposure;

i) the result of the test: cracking or fracture;

j) t/t;

k) hardness values.

An example of a typical Protocol is given in Appendix A.

Annex a (informative). Protocol for implant testing

Appendix A
(reference)

Manufacturer:

The objective of the audit:

_________________________________________________________________________

UDC 621.791.053:006.354 OKS 25.160.40

Key words: welded joints, arc welding, cold crack tested