Section 2 Materials
Clasification Society 2024 - Version 9.40
Clasifications Register Rules and Regulations - Rules and Regulations for the Classification of Inland Waterways Ships, July 2022 - Part 5 Main and Auxiliary Machinery - Chapter 2 Engines - Section 2 Materials

Section 2 Materials

Parent topic: Chapter 2 Engines

2.1 Crankshaft materials

2.1.1 The specified minimum tensile strength of castings and forgings for crankshafts is to be selected within the following general limits:

  1. Carbon and carbon-manganese steel castings – 400 to 550 N/mm2.

  2. Carbon and carbon-manganese steel forgings (normalised and tempered) – 400 to 600 N/mm2.

  3. Carbon and carbon-manganese steel forgings (quenched and tempered) – not exceeding 700 N/mm2.

  4. Alloy steel castings – not exceeding 700 N/mm2.

  5. Alloy steel forgings – not exceeding 1000 N/mm2.

  6. Spheroidal or nodular graphite iron castings – 370 to 800 N/mm2.

2.1.2 Where it is proposed to use alloy castings, micro alloyed or alloy steel forgings or iron castings, details of the chemical composition, heat treatment and mechanical properties are to be submitted for approval.

2.2 Material test and inspections

2.2.1 Components for engines are to be tested as indicated in Table 2.2.1 Test requirements for oil engine components and in accordance with the relevant requirements of the Rules for the Manufacture, Testing and Certification of Materials (hereinafter referred to as the Rules for Materials).

Table 2.2.1 Test requirements for oil engine components

Component Material tests Non-destructive tests
Magnetic particle Ultrasonic
or
Liquid penetrant
Crankshaft all all all
Steel piston crowns above 400 mm bore above 400 mm bore all
Connecting rods, including bearing caps all all above 400 mm bore
Cylinder liner above 300 mm bore – –
Cylinder cover above 300 mm bore above 400 mm bore all
Steel castings for welded bedplates all all all
Steel forgings for welded bedplates all – –
Plates for welded bedplates, frames and entablatures all – –
Crankcases, welded or cast all – –
Turbocharger, shaft and rotor above 300 mm bore – –
Steel gear wheels for camshaft drives above 400 mm bore above 400 mm bore –

Note 1. For closed-die forged crankshafts, the ultrasonic examination may be confined to the initial production and to subsequent occasional checks.

Note 2. Cylinder covers and liners manufactured from spheroidal or nodular graphite iron castings may not be suitable for ultrasonic NDE, depending upon the grain size and geometry. An alternative NDE procedure is to be agreed with LR.

Note 3. Bore dimensions refer to engine cylinder bores.

Note 4. All required material tests are to be witnessed by the Surveyor unless alternative arrangements have been specifically agreed by LR.

2.2.2 For components of novel design, special consideration will be given to the material test and non-destructive testing requirements.

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