ISO 9015-2:2016 download.Destructive tests on welds In metallic materials — Hardness testing — Part 2: Microhardness testing of welded joints.
This part of ISO 9015 specifies microhardness testing on transverse sections of welded joints of metallic materials with high hardness gradients. It covers Vickers hardness tests in accordance with ISO 6507-1, normally with test loads of 0,98 N to less than 49 N (HV 0.1 to less than HV 5).
NOTE Testing ensures that the highest and/or the Lowest level ot hardness at both parent nia(cnals (in the case of dissimilar materials both parent materials) and weki metal is determined.
This part of ISO 9015 is not applicable to hardness testing of welds with loads of 49,03 N and above. which is covered by ISO 90154.
This part of ISO 9015 Is not applicable to Vickers hardness testing of resistance spot, projection and seam welds, which Is covered by ISO 14271.
This part of ISO 9015 is not applicable to hardness testing of very narrow welds, e.g. those typically produced by laser and electron beam welding (see ISO 22826).
2 Normative references
The following documents. in whole or in part, are normatively referenced in ISO 9015-2 and are indispensable for its application. For dated references, only the edition cited applies. For undated references, the latest edition of the referenced document (including any amendments) applies.
ISO 6507-1, Metallic materials — Vickers hardness test — Pan 1: Test method
3 Symbols and abbreviated terms
The symbols and terms to be used are specified in ThLe..1 and represented in Figures 1.2 and 3.
4 Principle
Microhardness testing shall be carried out in accordance with ISO 6S071.
The mlcrohardness tests may be carried out in the form of rows of indentations, R, or as individual Indentations, E.
When the type of weld is not shown in the examples, the test procedure shall be appropriate to the welded joint.
In general, the test is carried out at ambient temperature within the limits of 10 C to 35 C. Tests carried out under controlled conditions shall be made at a temperature of (23 ± 5) °C.
S Preparation of test specimens
The preparation of the test specimen shall he In accordance with ISO S07.l.
A cross•sectlon from the test piece shall be taken by mechanical cutting, usually transverse to the welded joint.
This operation and the subsequent preparation of the surface shall be carried out carefully so that the hardness of the surface to be tested is not affected metallurgically by heat or cold working.
The surface to be tested shall be properly prepared and preferably etched, so that accurate measurements of the diagonal lengths of the indentations can be taken in the different zones of the welded joint.
6 Test procedure
6.1 Rows of Indentations (R)
Ftgures 1 and 2 show typical examples for the location of hardness Indentations made In rows, including the distance from the surface, so that the rows or parts thereof permit an assessment of the welded joint. If specified, e.g. by reference to an application standard, additional rows of indentations and/or different locations may be made. The actual location(s) shall be included in the test report.
In metals such as aluminium or copper and their alloys, the rows on the root-side of butt welds (see Figure 1) are not always necessary and may be omitted.
The number and spacing of indentations shall be sufficient to define hardened and/or softened regions due to welding. The recommended distance, L, between the centre point of the indentations in the heat- affected zone (IIAZ) is given In Table 2 and In ISO 6507.1. The larger dimension, In accordance wIth Tahle.2 or ISO i507-1. should be used.
A sufficient number of Indentations shall be made to ensure that unaffected parent material Is also tested. The distance between indentations in the weld metal shall be sufficient to enable a full assessment of the welded joint. For metals which, as a result of welding, harden in the HAZ, two additional Indentations In the IIAZ shall be made at a distance s 0,5 mm between the centre point of the indentation and the fusion line (see Figure 2).
For other joint configurations or metals (e.g. austenitic steels) additional indentations may be specified, e.g. by reference to an application standard.
6.2 Individual indentations (E)
Eigure shows typical areas for the location of individual indentations: locations 1—4 give Information about the unaffected parent material; locations 5-8 refer to the HAZ; locatIons 9-11 refer to the weld metal. Otherwise, the location of the indentation can be determined on the basis of metallographic examination,
To prevent the Influence of deformation caused by an Indentation, the minimum distance between the centre point of individual indentations in any direction shall not be less than the value given in ISO 6S07-1.
For metals that harden In the HAZ as a result of welding, at least one Indentation shall be made In the HAZ with its centre point sO.5 mm from the fusion line.
For hardness testing using Individual indentations, the areas shall be numbered as shown In Figure 3.
7 Test results
The hardness values shall be recorded in relation to the position of the indentation.
8 Test report
The test results shall be recorded in a test report, which contains at least the following Information:
a) type of hardness test;
b) Identification of the test machine;
c) parent material;
d) thickness of the material;
e) type oIwcld:
f) welding process;
g) consumable;
h) post weld heat treatment and br ageing;
i) any relevant notes:
j) a picture or drawing. with dimensions if appropriate.
The format given in Annex A and Annex B should be used.