Section 1 General requirements

1.1.1 This Section gives the general requirements for grey (flake), spheroidal (nodular) graphite and compacted (vermicular) graphite iron castings intended for use in the construction of ships, other marine structures, machinery, boilers, pressure vessels and piping systems.

1.1.2 Where required by the relevant Rules dealing with design and construction, castings are to be manufactured and tested in accordance with Ch 1 General Requirements and Ch 2 Testing Procedures for Metallic Materials, together with the requirements given in this Section and either Ch 7, 2 Grey iron castings for grey iron castings, Ch 7, 3 Spheroidal or nodular graphite iron castings for spheroidal graphite iron castings or Ch 7, 4 Compacted or vermicular graphite iron castings for compacted graphite iron castings. Castings for crankshafts are additionally to comply with the requirements detailed in Ch 7, 5 Iron castings for crankshafts.

1.1.3 As an alternative to Ch 7, 1.1 Scope 1.1.2, castings which comply with National or proprietary specifications may be accepted, provided that these specifications give reasonable equivalence to the requirements of this Chapter or alternatively are approved for a specific application. Generally, survey and certification are to be carried out in accordance with the requirements of Ch 1 General Requirements.

1.1.4 Where small castings are produced in large quantities, or where castings of the same type are produced in regular quantities, alternative survey procedures, in accordance with Ch 1, 2.2 LR Approval – General, may be adopted subject to approval by Clasifications Register (hereinafter referred as 'LR').

1.2.1 Castings as designated in Ch 7, 1.1 Scope 1.1.2 are to be made at foundries approved by LR.

1.2.2 Suitable mechanical methods are to be employed for the removal of surplus material from castings. Thermal cutting processes are not acceptable, except as a preliminary operation to mechanical methods.

1.3.1 Castings are to be free from surface or internal defects which would be prejudicial to their proper application in service. The surface finish is to be in accordance with good practice and any specific requirements of the approved plan.

1.4.1 The chemical composition of the iron used is left to the discretion of the manufacturer, who is to ensure that it is suitable to obtain the mechanical properties specified for the castings.

1.5.1 Except as required by Ch 7, 1.5 Heat treatment 1.5.2, castings may be supplied in either the as cast or heat treated condition.

1.5.2 For some applications, such as elevated temperature service, or where dimensional stability is important, castings may require to be given a suitable tempering or stress relieving heat treatment. This is to be carried out after any refining heat treatment and before machining.

1.5.3 Where it is proposed to carry out local hardening of the surface of a casting, full details of the proposed procedure are to be submitted for approval.

1.6.1 At least one test sample is to be provided for each casting or batch of castings. For large castings, where more than one ladle of metal is used, one test sample is to be provided, from each ladle used.

1.6.2 A batch testing procedure may be adopted for castings with a fettled mass of 1 tonne or less. All castings in a batch are to be of similar type and dimensions, and cast from the same ladle of metal. One test sample is to be provided for each multiple of two tonnes of fettled castings in the batch.

1.6.3 Where separately cast test samples are used, they are to be cast in moulds made from the same type of material as used for the castings and are not to be stripped from the moulds until the temperature is below 500°C.

1.6.4 All test samples are to be suitably marked to identify them with the castings which they represent.

1.6.5 Where castings are supplied in the heat treated condition, the test samples are to be heat treated together with the castings which they represent. For cast-on test samples, the sample is not to be separated from the casting until after heat treatment.

1.7.1 One tensile specimen is to be prepared from each test sample. The dimensions of the test specimens and the testing procedures used are to be in accordance with Ch 2 Testing Procedures for Metallic Materials.

1.7.2 The results of all tensile tests are to comply with the requirements given in Ch 7, 2 Grey iron castings, Ch 7, 3 Spheroidal or nodular graphite iron castings, Ch 7, 4 Compacted or vermicular graphite iron castingsor Ch 7, 5 Iron castings for crankshafts, as appropriate.

1.7.3 In the case of castings supplied in the as cast condition which initially do not meet the requirements of Ch 7, 1.7 Mechanical tests 1.7.2, the manufacturer, by agreement with the purchaser, has the right to heat treat the castings, together with the representative test samples, and re-submit them for acceptance.

1.7.4 In the case of a batch of castings supplied in the heat treated condition which initially do not meet the requirements of Ch 7, 1.7 Mechanical tests 1.7.2, the manufacturer has the right to re-heat treat the batch together with the representative test samples, and re-submit the castings for acceptance. The number of reheat treatments and retestings will be restricted to two.

1.8.1 All castings are to be cleaned and adequately prepared for examination. The surfaces are not to be hammered, peened or treated in any way which may obscure defects.

1.8.2 The accuracy and verification of dimensions are the responsibility of the manufacturer, unless otherwise agreed.

1.8.3 All castings are to be presented to the Surveyor for visual examination and this is to include the examination of internal surfaces where applicable.

1.8.4 The non-destructive examination of castings is not required unless otherwise stated in the approved plan or where there is reason to suspect the soundness of the casting.

1.8.5 In the event of any casting proving defective during subsequent machining or testing it is to be rejected notwithstanding any previous certification.

1.9.1 At the discretion of the Surveyor, small surface blemishes may be removed by local grinding.

1.9.2 Subject to the prior approval of the Surveyor, castings containing local porosity may be rectified by vacuum impregnation with a suitable plastic filler, provided that the extent of the porosity is such that it does not adversely affect the strength of the casting.

1.9.3 Repairs by welding are not permitted on grey cast iron castings or compacted graphite iron castings and generally not permitted for spheroidal or nodular graphite iron castings, but may be considered in special circumstances for spheroidal or nodular graphite iron castings. In such cases, full details of the proposed repair procedure are to be submitted for approval prior to the commencement of the proposed rectification.

1.10.1 When required by the relevant Rules, castings are to be pressure tested before final acceptance. These tests are to be carried out in the presence and to the satisfaction of the Surveyor.

1.11.1 The manufacturer is to adopt a system of identification, as per the requirements of Ch 1, 4.8 Identification of materials, which will enable all finished castings to be traced to the original cast, and the surveyor is to be given full facilities for tracing the castings, when required.

1.11.2 Before acceptance, all castings which have been tested and inspected with satisfactory results are to be clearly marked by the manufacturer with the following particulars:

1. Type and grade of cast iron.

2. Identification number, cast number or other marking which will enable the full history of the casting to be traced.

3. Manufacturer's name or trade mark.

4. LR or Clasifications Register and the abbreviated name of LR's local office.

5. Personal stamp of Surveyor responsible for inspection.

6. Test pressure, where applicable.

7. Date of final inspection.

1.11.3 Where small castings are manufactured in large numbers, modified arrangements for identification may be specially agreed with the Surveyor.

1.12.1 A LR certificate is to be issued, see Ch 1, 3.1 General.

1.12.2 The manufacturer is to provide the Surveyor with a written statement giving the following particulars for each casting or batch of castings which has been accepted:

1. Purchaser's name and order number.

2. Description of castings and quality of cast iron.

3. Identification number.

4. General details of heat treatment, where applicable.

5. Results of mechanical tests.

6. Test pressure, where applicable.

7. When specially required, the chemical analysis of ladle samples.

1.12.3 Where applicable, the manufacturer is to provide a signed statement regarding non-destructive testing as required by Ch 7, 1.8 Visual and non-destructive examination, together with a statement and/or a sketch detailing the extent and position of all weld repairs made to each casting as required by Ch 7, 1.9 Rectification of defective castings.