Section 5 Castings

501. Steel castings

1. Chemical composition

(1) In application to 501. 4 of the Rules, the chemical composition of special carbon steel casting with higher toughness requirements such as high holding power anchors etc. is to comply with the requirements of Table 2.1.11 of the Guidance.

The suitable grain refining elements such as aluminium etc. are to be used at the discretion of the manufacturer. The content of such elements is to be reported in the ladle analysis.

Table 2.1.11 Chemical Composition

(2) "Subject to approval by the Society," referred in note (1), Table 2.1.69 of 501. 4 of the Rules means only where welding procedure qualification test of the casting for welded construction with same chemical composition has been satisfied by the Society

2. Mechanical properties

(1) In application to

501.

6. (2) of the Rules, the results of impact test is to comply with the re-

quirements of Table 2.1.12 of the Guidance.

Table 2.1.12 Impact Test Requirements

(2) In application to 501. 6. (2) of the Rules, carbon steel castings intended for welded con- struction which required impact test includes upper rudder casting.

3. Surface and dimension inspection

The surface inspection of stern frames, rudder frames and crank shaft specified in 501. 8 of the Rules are to be dealt with as follows :

(1) The surface inspection of stern frame and rudder frame are to comply with the Annex 2-2.

(2) The surface inspection of crank shafts made of steel castings are to comply with the Annex 2-3.

4. Non-destructive inspection

The non-destructive inspection for steel castings specified in 501. 10 (1) and (2) of the Rules are to be dealt with as follows :

(1) The non-destructive inspection of stern frame and rudder frame are to comply with the Annex 2-2.

(2) The non-destructive inspection of crank shafts made of steel castings are to comply with the

Annex 2-3.

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5. Repair of defects

Repairs by welding for steel casting specified in 501. 11 (1), (b) of the Rules are to be dealt with as follows :

(1) Repairs by welding of crank throws made of steel castings are to comply with the Annex 2-4.

(2) Repairs by welding of steel alloy castings are to comply with 7 (the preparatory tests) of the

Annex 2-4.

(3) Repairs of steel castings such as stern frame, rudder frame and others intended for important parts of hull structure are to comply with the Annex 2-2, 8.

502. Steel castings for chains

Steel castings for offshore mooring chain are to comply with Annex 2-9, 4 of this guidance.

505. Stainless steel casting for propeller

1. Application

"agreement with the Society" referred in 505. 1 (1) of the Rules includes the possible normal oper- ation throughout the repair of propellers damaged in service.

2. Non-destructive inspection

(1) The liquid penetrant test of steel propeller casting specified in 505. 8 (1) of the Rules is to comply with Annex 2-6.

(2) The division of severity zones of steel propeller casting specified in 505. 8 (2) is to comply with the Figs. 1 and 2 of Annex 2-6.

3. Repair of defects

In application to 505. 9 (4) of the Rules, the repair welding procedure is to comply with the fol- lowings

(1) The limits of repair welding are to comply with Annex 2-6, 3 (2) to (4).

(2) Repair welding procedure

When steel propeller casting is repaired by welding in accordance with the previous (1), the fol- lowing requirements apply.

(A) Before welding is started, a detailed welding procedure specification is to be submitted cov- ering the weld preparation, welding positions, welding parameters, welding consumables, preheating, post weld heat treatment and inspection procedures to the Society. The welding procedure qualification tests are to carried out in accordance with following (3).

(B) All weld repairs are to be made by welders qualified as deemed appropriate by the Society.

(C) Welding is to be done under controlled conditions free from draughts and adverse weather.

(D) The welding consumables used in the welding procedure qualification tests are to be used.

The welding consumables are to be stored and handled in accordance with the manu- facturer’s recommendations.

(E) The martensitic steels are to be furnace re-tempered after weld repair. Subject to prior ap- proval of the Society, however, local stress relieving may be considered for minor repairs.

(F) On completion of heat treatment the weld repairs and adjacent material are to be ground smooth. All weld repairs are to be liquid penetrant tested.

(G) The foundry is to maintain records of welding, subsequent heat treatment and inspections traceable to each casting repaired. These records are to be reviewed by the Surveyor.

(3) Welding procedure qualification test

(A) Preparation of test sample

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The test sample is to be as shown Fig 2.1.3 of the Guidance. The edge preparation, in principle, to be V-shape and bevel angle is to be not less than 60°.

(B) Non-destructive testing

The test sample is to be visually inspected and liquid penetrant tested.

(C) Macro-structure examination

Two macro-sections shall be prepared. No pores greater than 3 mm and cracks in welded sections is permitted.

Fig 2.1.3 Test Sample for Butt Welding Test

(D) Tensile testing

Two flat transverse tensile test specimens shall be prepared. The tensile strength shall meet the specified minimum value of the base material. The location of fracture is to be reported,

i.e. weld metal, HAZ or base material.

(E) Bend testing

Two transverse side bend test specimens shall be prepared . The former diameter shall be 4 x thickness except for austenitic steels, in which case the former diameter shall be 3 x thickness.

The test specimen, when visually inspected after bending, shall show no surface im- perfections greater than 2 mm in length.

(F) Impact testing

Impact test is not required, except where the base material is impact tested. Two sets shall be taken, one set with the notch positioned in the center of the weld and one set with the notch positioned in the fusion line, respectively. The test temperature, and impact energy shall comply with the requirement specified for the base material.

(G) Hardness testing

One of the macro-sections shall be used for Hv5 hardness testing. At least three individual indentations in the weld metal, the HAZ (both sides) and in the base material. The values are to be reported for information.

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506. Grey iron casting

1. Application

"deemed necessary by the Society" referred in 506. 1 (2) of the Rules means where it is applicable

for the other materials than the specified ones in Pt

2. Test samples

2 of the Rules.

The chill test specified in 506. 6 (7), (d) of the Rules is to comply with A STM A367-60(Standard test methods of chill tests of cast iron.

507. Spheroidal or nodular graphite iron castings

1. Application

(1) In application to 507. 1 (2) of the Rules, the term "additional requirements" means the accept- ance in accordance with Pt 1, Ch 1, 104. or 105. of the Guidance.

(2) "deemed necessary by the Society" referred in 507. 1 (3) of the Rules means where it is appli-

cable for the other materials than the specified ones in Pt 2 of the Rules.

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