DNVGL-CP-0248 Edition May 2016

Transcription

1 CLASS PROGRAMME Approval of manufacturers DNVGL-CP-0248 Edition May 2016 The content of this service document is the subject of intellectual property rights reserved by ("DNV GL"). The user accepts that it is prohibited by anyone else but DNV GL and/or its licensees to offer and/or perform classification, certification and/or verification services, including the issuance of certificates and/or declarations of conformity, wholly or partly, on the basis of and/or pursuant to this document whether free of charge or chargeable, without DNV GL's prior written consent. DNV GL is not responsible for the consequences arising from any use of this document by others. The electronic pdf version of this document, available free of charge from is the officially binding version.

2 FOREWORD DNV GL class programmes contain procedural and technical requirements including acceptance criteria for obtaining and retaining certificates for objects and organisations related to classification. May 2016 Any comments may be sent by to This service document has been prepared based on available knowledge, technology and/or information at the time of issuance of this document. The use of this document by others than DNV GL is at the user's sole risk. DNV GL does not accept any liability or responsibility for loss or damages resulting from any use of this document.

3 CHANGES CURRENT This is a new document. Changes - current Class programme DNVGL-CP Edition May 2016 Page 3

4 CONTENTS Changes current... 3 Contents Section 1 General Objective Scope and application Request for approval References... 6 Section 2 Documentation requirements Manufacturing summary Aluminium melting shop Conditioning of semi-finished aluminium Reheating and processing Cleaning and finishing Heat treatment Other records, test facilities and procedures Test results and records...8 Section 3 Approval testing Test products and testing scope Testing requirements...10 Changes historic...13 Class programme DNVGL-CP Edition May 2016 Page 4

5 SECTION 1 GENERAL 1 Objective The objective of this class programme (CP) is to provide a description for which the Society bases its approval of manufacturers intending to supply wrought aluminium alloy products in accordance with RU SHIP Pt.2 or other applicable standards provided by the Society. Section 1 2 Scope and application This programme is applicable for the approval of material manufacturers of:, 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. 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 aluminium grade and temper, and each of the following manufacturing processes/product groups. For each product group, the approval is further limited to the parameters indicated as follows: rolled products maximum thickness heat treatment/delivery condition extruded products profile shape and type (open or closed) maximum thickness heat treatment/delivery condition drawn products maximum thickness heat treatment/delivery condition forged products maximum product mass maximum product thickness heat treatment/delivery condition. Subject to agreement with the Society, soft/annealed tempers may be covered by the higher strength tempers., e.g. approval test of 6xxx alloys of temper T5/T6 may cover approval of the T4 temper, and approval test of 5xxx alloys of delivery condition H321 may cover the tempers O and H111. Approval of the manufacturer may also be given for the additional condition including low temperature service, for the applicable grades after appropriate testing. Approval will be given for the manufacture of products and materials in accordance with the DNV GL rule requirements. However, in the absence of relevant DNV GL rules and subject to agreement with the Society, approval may be given for the manufacture of products and materials specified in recognised standards. Manufacturer s own heat treatment facilities shall be evaluated and approved by the Society either under this approval program or as approved "heat-treatment workshop" through the separate approval programme DNVGL CP In case any manufacturing steps are performed by a sub-supplier, the Society may require corresponding approval of the sub-supplier where relevant. Class programme DNVGL-CP Edition May 2016 Page 5

6 3 Request for approval When applying for AoM, the manufacturer shall indicate the material grades to be covered by the approval, including manufacturing method, dimensions, heat treatment and delivery conditions as per [3]. For this a list or table shall be provided, which shall include: type of products manufacturing method as part of manufacturing summary range of applicable product sizes (dimensions and weight) applicable grades and tempers delivery conditions starting material, its shape and material certificate reference to DNV GL rules for the applicable chemical composition, mechanical properties and heat treatment. Where agreed with the Society, reference may be made to a recognised standard. Section 1 4 References Table 1 List of references No. Reference Title 1 ASTM B928 Standard specification for high magnesium aluminium-alloy sheet and plate for marine service and similar environments 2 ASTM G66 Standard test method for visual assessment of exfoliation corrosion susceptibility of 5XXX series aluminium alloys (ASSET Test) 3 ASTM G67 Standard test method for determining the susceptibility to intergranular corrosion of 5XXX Series aluminium alloys by mass loss after exposure to Nitric Acid (NAMLT Test). Class programme DNVGL-CP Edition May 2016 Page 6

7 SECTION 2 DOCUMENTATION REQUIREMENTS 1 Manufacturing summary Manufacturer shall submit information about the specific manufacturing process and related production records for products for which approval is requested. Documentation shall also include manufacturer s metallurgical specifications related the manufacturing process as described in this section. Section 2 2 Aluminium melting shop The following documentation shall be submitted: type of furnace and capacity furnace charge composition, e.g. ingots, scrap, foundry returns metal treatment, e.g. removal of hydrogen, non-metallic inclusions and impurity elements, additions of alloying and grain refining elements slab/billet size and weight homogenisation of slabs/billets. 3 Conditioning of semi-finished aluminium The following documentation shall be submitted: slab/billet machining non-destructive testing of slab/billet. 4 Reheating and processing The following documentation shall be submitted: type and description of processing equipment reheating temperature and time in furnace a detailed description of the processing schedule including: temperature ranges and reduction ratios for forging processes: sketch of the forming operations cooling conditions after processing finishing processes (any cold deformation process including stretching). 5 Cleaning and finishing The following documentation shall be submitted: method of surface cleaning method of surplus metal removal (de-burring). 6 Heat treatment The following documentation shall be submitted: type of furnace and dimensions heating source sketch indicating the positions of thermocouples working zone dimension and sketch of working zone accuracy and calibration status of temperature control devices furnace uniformity test report Class programme DNVGL-CP Edition May 2016 Page 7

8 furnace loading pan and procedure heat treatment procedures, specifying temperatures and holding times, and where applicable, information about heating and cooling rates, quenching medium and cooling medium after tempering records of heat treatment any re-heat treatment procedure to be given, if applicable method of cleaning after heat treatment. Section 2 7 Other records, test facilities and procedures The following documentation shall be submitted: visual inspection: relevant templates for recording, and a few records of previously performed visual inspections of same or similar products details and description of relevant in-house testing facilities and calibration details, test procedures and qualification of testing personnel NDT procedures, equipment for NDT including calibration details, and qualification of personnel for NDT information and procedures about important manufacturing and testing routines, such as cutting and macrographic inspection of products etc. 8 Test results and records Additional requirements for reporting of test results: Sampling: sketches, drawings and photos showing the position of test blocks shall be submitted. Type of test blocks and their dimensions shall be reported and where applicable, reference shall be made to relevant DNV GL rules or recognised standards. Chemical composition: a summary of the sampling practices and methods for chemical analysis is to be submitted the chemical composition shall be reported in percentage by mass the report shall give the specified limits and the measured content of all the required elements. Tensile test: yield (or proof) stress, tensile strength, elongation shall be reported. Press weld testing of closed profile extrusions: test results shall be reported and documented by photos. Metallographic examination: high quality photomicrographs showing the microstructure at 100x and 500x magnification shall be presented with a brief description. The magnification shall be indicated on the micrographs by a line symbol, e.g. with length of 0.5 mm or 100 µm. Arrows or letters may be used to identify features referred to in the report a short description of the microstructure shall be provided with each micrograph the applied etching methods for the metallographic examination shall be stated in the report. Corrosion testing (if applicable) reporting shall be in the format given in the reference test standard. for relationship between microstructure and resistance to corrosion (if applicable): upon satisfactory establishment of the relationship between microstructure and resistance to corrosion, the reference photomicrographs and the results of the corrosion tests shall be submitted for approval. Class programme DNVGL-CP Edition May 2016 Page 8

9 Visual examination: report/record for visual inspection, dimensional measurements and surface condition. Section 2 Class programme DNVGL-CP Edition May 2016 Page 9

10 SECTION 3 APPROVAL TESTING 1 Test products and testing scope 1.1 General The test products are to be selected so that the intended approval scope as outlined in Sec.1 [3] is covered. Section Extent of approval testing For each selected product type, material grade and temper condition, testing shall be carried out on at least two heats where one heat shall represent maximum thickness/diameter (dimension) and another heat should represent an average thickness/diameter of the product for which approval is requested. Extrusions selected for approval testing should be representative for all profile types (i.e. open or closed) and shapes for which approval is requested. 1.3 Selection and position of the test samples The products for testing shall be representative of the dimensions for which approval is requested. Test samples from which test specimens are taken, shall be integral with the products. The position of test specimens within the test samples shall be in accordance with the relevant rule requirements. Test samples shall be taken out in final delivery condition and shall not be subjected to any separate heat treatment. For ingot cast materials, the test product shall be made from the first ingot from the ladle. For continuous cast materials, the test product shall be made from the tail end of the string (i.e. the material poured when the ladle is nearly empty). Where samples from one end of the product are referred in the following, it means the end corresponding to the top of the ingot for ingot cast material, or the end corresponding to the tail end of the string for continuous cast material. Where samples from both ends of the product are referred in the following, it means the locations on the final product corresponding to the former ends of the ingot/slab/bloom/billet applied for testing (after cutting of discard). Unless specified in the rules sampling positions may be proposed by the manufacturer and agreed with the Society on case by case basis. 2 Testing requirements 2.1 Chemical composition The following are required: chemical composition shall be determined both by heat and by product analysis and shall comprise all the elements required by relevant DNV GL rules. The analyses shall also comprise as any other elements intentionally added or designated as residual elements a summary of the sampling practices and methods for chemical analysis shall be prepared. 2.2 Tensile testing The following are required: the tests shall represent both ends of the product, i.e. two tensile tests shall be made from each product. Class programme DNVGL-CP Edition May 2016 Page 10

11 2.3 Press weld testing of closed profile extrusions The following are required: proper fusion of press welds for closed profile extrusions shall be verified by one macro section and one drift expansion test from each end of the extruded products other tests replacing the drift expansion test may be accepted by the Society after special consideration. Section Metallographic examination The following are required: one specimen shall be sampled near the surface and one specimen at the mid-wall thickness of the test block. The test block shall be made from mid width of the product, at one end of a coil or at a random location for sheets and plates for rolled plates: a longitudinal section perpendicular to the rolled surface shall be prepared. The microstructure shall be compared to the reference photomicrograph of acceptable material high quality photomicrographs showing the microstructure at 100x and 500x magnification shall be prepared with a brief description. The magnification shall be indicated on the micrographs by a line symbol, e.g. with length of 0.5 mm or 100 µm. Arrows or letters may be used to identify features referred to in the report. 2.5 Corrosion testing (if applicable) The following are required: rolled plates of grades 5083, 5383, 5059, 5086 and 5456 in the H116 or H321 tempers shall be tested with respect to exfoliation and inter-granular corrosion resistance according to DNV GL rules test for resistance to corrosion shall be performed for all applicable grades/tempers. Surface finish of the test specimens shall be representative of the surface finish of the material/product in final supply condition the acceptance criteria for the tests are given by the DNV GL rules reporting shall be in the format given in the reference test standard. 2.6 Relationship between microstructure and resistance to corrosion (if applicable) The following are required: for plates that require exfoliation and inter-granular corrosion the manufacturer shall establish the relationship between microstructure and resistance to corrosion a reference photomicrograph taken at 500x, under the conditions specified in ASTM B928, shall be established for each of the alloys for each of the applicable tempers and for each thickness ranges as relevant. The reference photographs shall be taken from samples which have exhibited no evidence of exfoliation corrosion and a pitting rating of PB or better, when subjected to the test described in ASTM G66 (ASSET). The samples shall also have exhibited resistance to inter-granular corrosion at a mass loss no greater than 15 mg/cm 2, when subjected to the test described in ASTM G67 upon satisfactory establishment of the relationship between microstructure and resistance to corrosion, the reference photomicrographs and the results of the corrosion tests shall be approved by the Society production practices shall not be changed after approval of the reference micrographs. Class programme DNVGL-CP Edition May 2016 Page 11

12 2.7 Visual examination The following are required: visual examination shall be conducted according to the relevant rule requirements the surfaces shall be adequately prepared for inspection the surfaces shall not be hammered, peened or treated in any way which may obscure discontinuities examination shall be done for all applicable sides and areas, and manufacturer shall ensure that lifting devices for handling and turning of the products are available when relevant visual examination shall include internal surfaces measurements shall be made on all applicable dimensions manufacturer shall present representative products used for approval purpose including reports for visual inspection of the products and surface condition. Section Other tests (if applicable) In case other tests, e.g. pressure testing etc. are required by the referred rules/standard, the type of test and test results shall be submitted. Class programme DNVGL-CP Edition May 2016 Page 12

13 CHANGES HISTORIC There are currently no historical changes for this document. Changes historic Class programme DNVGL-CP Edition May 2016 Page 13

14 DNV GL Driven by our purpose of safeguarding life, property and the environment, DNV GL enables organizations to advance the safety and sustainability of their business. We provide classification and technical assurance along with software and independent expert advisory services to the maritime, oil and gas, and energy industries. We also provide certification services to customers across a wide range of industries. Operating in more than 100 countries, our professionals are dedicated to helping our customers make the world safer, smarter and greener. SAFER, SMARTER, GREENER