DNV DNVGL-CP-0247 PDF

Scope and application

This programme is applicable for the approval of manufacturers of:

Steel forgings,

as referred in the Society's rules and standards. For a description of general requirements, conditions and procedures related to the approval, please refer to DNVGL CP 0346 which shall be applied in combination with this programme.

This AoM programme is applicable for the approval of manufacturers of products indicated in Table 1 as per DNV GL rules and standards.

The product(s) used for approval testing (see Sec.3) will place limitations on the range of approval. The approval will be limited to:

each steel type group or material grade (see App.A)

carbon and carbon-manganese (C and C-Mn) steels

the individual alloy steels

the individual stainless steels

each application area, see Table 1

forging method

maximum forging weight

maximum cross section and diameter

heat treatment and delivery condition

the reduction ratio for the products for approval testing shall be representative for the later production of the similar products.

When applicable, specific approval will be given on the certificate for the following additional conditions:

continuous grain flow (CGF) crankshafts or crank throws; according to DNVGL CG 0037

specially approved forging process; as referred in the rules RU SHIP Pt.4 and DNVGL CG 0036

clean steel forgings; according to DNV GL rules RU SHIP Pt.2 Ch.2 Sec.6

approved steel grades for low temperature service.

The approval is limited to the material grade for which approval tests are carried out, but certain grades may also cover other grades in the same steel type group, or the entire steel type group, as explained in App.A.

Where steel forgings are to be repaired by welding (see guidance note), or two or more items are joined by welding to form a composite item, the manufacturer's welding shop shall either be approved for welding in accordance with this programme, or be approved as welding workshop. For welding workshop approval, see DNVGL CP 0352.

The manufacturer’s own heat treatment facilities shall be evaluated and approved by the Society, either under this approval programme, or as an approved "heat-treatment workshop" based on the approval programme DNVGL CP 0351.

Where heat treatment or case hardening is performed by a sub supplier, the sub supplier shall be approved by the Society as a heat treatment workshop in accordance with DNVGL CP 0351.

Starting material/semi-finished steel products shall be produced at works approved by the Society.

For steel forges operates their own steel making and produce their semi-finished steel products (slabs/ingots/ etc.), the approval programme DNVGL CP 0242 shall be used to approve these facilities.