Section 3 Material testing, test specimen and mechanical properties

3.1.1 Material specifications for high manganese austenitic steel plates are defined in Table 2.3.1 Mechanical properties for high manganese austenitic steel .

3.2.1 The material’s surface quality, internal soundness and dimensional tolerances are to comply with Ch 3, 1.5 Surface quality of materials, Ch 3, 1.6 Internal soundness and Ch 3, 1.7 Dimensional tolerances, respectively, of the Rules for the Manufacture, Testing and Certification of Materials, July 2022.

3.3.1 The general requirement for inspection of high manganese steel is to comply with Ch 3, 1 General requirements of the Rules for the Manufacture, Testing and Certification of Materials, July 2022.

3.4.1 All material in a batch presented for acceptance tests is to be of the same product formed from the same cast and in the same condition of supply.

3.4.2 The test samples are to be fully representative of the material and, where appropriate, are not to be cut from the material until heat treatment has been completed.

3.4.3 The test specimens are not to be heat-treated separately from the test samples in any way.

3.4.4 Unless otherwise agreed, the test samples are to be taken from one end at a position approximately midway between the axis in the direction of rolling and the edge of the rolled product (see Figure 2.3.1 The location of the test sample). Unless otherwise agreed, the tensile test specimens are to be prepared with their longitudinal axis transverse to the final direction of rolling.

Figure 2.3.1 The location of the test sample

3.5.1 Tensile test specimens: The dimensions of the tensile test specimens are to be in accordance with Ch 2, 2 Tensile tests of the Rules for the Manufacture, Testing and Certification of Materials, July 2022. Test specimens of full product thickness are to be used.

3.5.2 Impact test specimens: The impact test specimens are to be of the Charpy V-notch type, cut with their longitudinal axis as near as practicable to a point midway between the surface and the centre of the thickness and either parallel or transverse to the final direction of rolling of the material. The notch should be cut in a face of the test specimen which was originally perpendicular to the rolled surface. The position of the notch is not to be nearer than 25 mm to a flame cut or sheared edge.

3.6.1 Number of tensile tests: One tensile test should be made from each piece.

3.6.2 Number of impact tests: At least one set of three Charpy V-notch test specimens should be made from each piece.

3.6.3 Re-test procedures for tensile tests and Charpy impact tests are to be in accordance with Ch 2, 1.4 Re-testing procedures of the Rules for the Manufacture, Testing and Certification of Materials, July 2022.

3.6.4 If any test specimen fails because of faulty preparation, visible defects or (in the case of tensile tests) fracturing outside the range permitted for the appropriate gauge length, the defective test piece may, at the Surveyor’s discretion, be disregarded and replaced by a new test specimen prepared from the material adjacent to the original test.

3.6.5 In the event of any material proving unsatisfactory during subsequent working or fabrication, such material may be rejected, notwithstanding any previous satisfactory testing and/or certification.