DNV DNV-RU-SHIPS PART 2 CHAPTER 2 [ Revised ]

This subsection specifies the general requirements for hot rolled steel products, i.e. plates/sheets, wide flats, strips, structural sections, structural hollow sections including structural pipes, and bars, see Figure 1, for use in the construction of hulls and other marine structures.

For limitations to fabrication of welded hollow sections by hot or cold forming, see also Ch.4 Sec.6 [6].

Requirements for hot rolled round steel bars for non-structural application, e.g. intended for shafts, tie rods and bolts are given in Sec.6.

For normal and high strength steels, the requirements apply to plates and wide flats not exceeding 150 mm in thickness and sections and bars not exceeding 50 mm in thickness, unless otherwise approved. For greater thicknesses, variations in the requirements may be permitted for particular applications, i.e. based on case-by-case approval.

For extra high strength steels, the requirements apply to plates, wide flats and bars not exceeding 250 mm in thickness, tubulars not exceeding 65 mm in thickness, and sections not exceeding 50 mm in thickness, unless otherwise approved.

For greater thicknesses, variations in the requirements may be permitted for particular applications, i.e. based on case-by-case approval.

Where required by the relevant design and construction parts of the rules, steel shall comply with the requirements of Ch.1, the general requirements of Sec.1 and the appropriate specific requirements of this section. If the specific requirements differ from these general requirements, the specific requirements shall prevail.

Steels differing from the specific requirements given in this section e.g. with respect to chemical composition, deoxidation practice, conditions of supply or mechanical properties may be accepted, subject to special approval. Such steels shall have the letter S appended to the corresponding NV grade, e.g. NV A36S.

Subject to approval and as an alternative to [1.1.3] and [1.1.4], materials which comply with other standards or proprietary specifications may be considered for acceptance provided such specifications give reasonable equivalence to the requirements of this section, or are approved case-by-case for a specific application, see Ch.1 Sec.1 [3.4].