MODUK DEF STAN 02-747: PART 3 PDF

This Standard provides requirements for the physical characteristics, test methods and acceptance standards of cast metal nickel aluminium bronze (NAB) commercial alloy ingots and sand castings.

Surface Ships

a) For surface ships this Standard may be used for:

i) Propellers if stated in the contract (See Def Stan 02-304 Part 1);

ii) Class I and II castings provided they are not in contact with sea water;

iii) Class III castings in accordance with Def Stan 02-863;

iv) Class I and II large or complex castings if stated in the contract.

Submarines

a) This Standard does not cover the use of the castings for submarine first level systems and submarine castings that may come into contact with sea water.

b) This alloy may be used for submarine propellers if stated in the contract (See Def Stan 02- 304 Part 3).

NOTE The material covered by this Def Stan suffers from selective phase corrosion (SPC) in the presence of sea water, particularly if the material has been weld repaired. Alternative NAB alloys (Def Stan 02-747 Part 2 and Def Stan 02-747 Part 4) reportedly less susceptible to SPC, and a copper-nickel-chromium alloy (Def Stan 02-824 Part 1) not susceptible to SPC, are available for use where this form of corrosion cannot be tolerated.

Classification of Castings

The classification of castings is defined in Def Stan 02-863.