1、THE ENGINEERING EQUIPMENT AND MATERIALS USERS ASSOCIATION SPECIFICATION FOR STRUCTURAL CASTINGS FOR USE OFFSHORE PUBLICATION No 176 : 1998 Copyright 1998 The Engineering Equipment and Materials Users Association ISBN O 85931 061 2 45 Beech Street LONDON EC2Y 8AD Telephone: 017 1-628 7878 Fax: 0171-6
2、28 7862 I EEMUA e-mail saleseemua.co.uk websi te www. eemua Co. uk THE ENGINEERING EQUIPMENT AND MATERIALS USERS ASSOCIATION The Engineering Equipment and Materials Users Association-EEMUA-was formed in-1983 by the Amalgamation of the Oil Companies Materials Association (OCMA) and the Engineering Eq
3、uipment Users Association (EEUA). it is an organisation of substantial purchasers and users of engineering products, whose members include leading national and multi-national companies in the petroleum, gas, chemical and energy industries. A list of Full and Associate Members (the latter being limit
4、ed to membership of three technical committees) is given below. EEMUA is concerned with the design, installation, operation and maintenance of the engineering plant used by members in pursuing their business activities. The Association aims to reduce members costs by providing the opportunity for th
5、em to share resources and expertise in order to keep abreast of technological developments and improve the effectiveness and efficiency of their engineering activities. EEMUA supports the British Standards Institution, works with other institutions, associations, government departments, regulatory a
6、uthorities and the Confederation of British Industry, and is also actively involved with other standards-making bodies, both national and international, such as the American Petroleum institute. Work, which is carried out in-house by members alone or with the help of other organisations, may lead to
7、 the production of Association publications. These are prepared primarily for members use, but are usually offered for sale and thus for more general use. Such publications may also be submitted, normally through the British Standards Institution, as bases for appropriate national, European or inter
8、national standards. A list of current EEMUA miblications which may be purchased from the Association is given at the end of this document. Full Members Associated Octel BG BP Ammo Caltex Petroleum Conoco Dow Corning Eastern Generation Esso/ExxonMobil Eutech Foster Wheeler Energy Lindsey Oil Refinery
9、 National Power PowerGen Shell Associate Members AstraZeneca BASF D the minimum ladle pouring temperature; and the methods of monitoring. Steelmaking All steel shall be produced by the basic electric-arc process followed by secondary vessel refining to obtain the specified properties. Alternatively,
10、 basic oxygen steel-making practices may be utilised. All steel shall be fully killed and made to fine grain practice. casting Where castings are made from more than one heat, adequate controls shall be exercised over chemical composition and over melting and pouring practice in order to ensure cons
11、istency of product. All flame cutting, scarfing or arc air gouging to remove surplus metal shall be to an accepted procedure and shall be performed before final heat treatment. Feeder heads and risers shall be removed by cutting at a sufficient distance above the surface of the casting to avoid dama
12、ge, followed by grinding flush. If damage to the casting occurs, the cutting distance shall be increased for subsequent removals. The method of thermal cutting and the minimum preheating requirements for head removal shall be included in the Suppliers procedure. Heat Treatment Heat treatment shall b
13、e carried out in a suitable furnace to an agreed procedure and shall consist of either double normalising and tempering, or quench and tempering, unless otherwise agreed by the mirchaser. The furnace shall be either electrically or gas heated with a neutral atmosphere. The soaking temperature and ti
14、me shall be in accordance with the agreed manufacturing procedure. The temperature of each casting during heat treatment shall be determined by thermocouples in effective contact with the casting. A minimum of six thermocouples per furnace load shall be used. 11 - STD-EEMUA PUB NO L7b-ENGL 1778 57bb
15、734 ULlUL9L 977 The Supplier shall submit for the Purchasers approval a procedure for heat treatment which shall include (with tolerances as appropriate): O O O O O heat treatment temperature and holding time temperatures at which castings are loaded into and unloaded from the furnace location of ca
16、stings in the furnace heating and cooling rates (maxima and minima) temperature control devices-their locations, means of attachment and recording methods maximum temperature gradients within the furnace thermocouples-methods of attachment, number and location on each casting. 5.4.3 All test blocks
17、shall be subjected to the same heat treatment as the production castings. Each test block shall be monitored by attaching thermocouples to ensure heat treatment identical to that of the production castings. 5.4.4 All thermocouples and temperature recorders shall have been calibrated within the three
18、 months prior to heat treatment of the castings, as evidenced by valid calibration certificates. 5.4.5 Heat treatment curves shall be supplied for each furnace charge and shall record the full heat treatment cycle. 5.4.6 Castings shall be tempered or thermally stress relieved after all repair weldin
19、g has been completed. 5.5 Welding 5.5.1 Any structural welds used in the manufacture of a component shall comply with the requirements of EEMUA 158. 5.5.2 Any repair welding to a casting shall be carried out in accordance with Sec. 9 and Appendix B of this Specification. 12 STD.EEMUA PUB NO L7b-ENGL
20、 3998 m 57bb734 0003892 803 m 6. CHEMICAL PROPERTIES 6.1 Composition Ladle and product analyses shall be provided by the Supplier for each casting. Acceptance of castings shall be based on their product analyses. The Supplier shall, at the enquiry stage, stat his aim and range for ladle and product
21、analyses including deliberate alloying additions and residual elements including boron, nitrogen, phosphorus, sulphur, copper, tin, antimony and lead. The Supplier shall make no other deliberate additions without prior agreement of the Purchaser. The analysis agreed at this stage will be included as
22、 an addendum to this Specification, and shall be the basis upon which the material is supplied and accepted. 6.2 Carbon Equivalent Carbon equivalent (CE) shall be calculated from product analysis in accordance with the formula: CE = C + Mn/6 + (Cr+Mo+V)/S + (Cu+Ni)/lS and shall not exceed 0.48. 6.3
23、Test Samples Samples for product analysis shall be taken from a test block representative of each casting. 6.4 Re-tests If any product analysis result falls outside the agreed limits, further analyses shall be undertaken on material representative of each casting from that heat. If the results again
24、 fail to meet the requirements, the Supplier shall provide for consideration by the Purchaser a detailed assessment of the implications of this on the suitability of the casting(s). 13 STD-EEMUA PUB NO L7b-ENGL 7. MECHANICAL PROPERTIES 7.1 7.1.1 7.1.2 7.1.3 7.1.4 7.1.5 7.1.6 7.2 7.2.1 7.2.2 Cast Tes
25、t Blocks 57bb734 0001893 74T A minimum of two test blocks shall be cast with each casting. At least one shall be integral with the body of the casting, and shall represent the casting minimum wall thickness. At least one shall be a separately gated cast block representing the maximum casting thickne
26、ss. The test blocks shall not be detached from the casting until all manufacturing heat treatments have been completed. The test blocks may be removed prior to simulated PWHT of casting repair welds. The dimensions and number of test blocks shall be sufficient to provide enough material to make the
27、required number of mechanical test specimens specified in this document. The Purchaser will stipulate in the order any additional test blocks which may be needed by the structural fabricator for weld procedure testing, CTOD testing, or other test. The Purchaser will also specify any PWHT cycles to w
28、hich such test blocks will be subjected by the Supplier. The Supplier shall be responsible for producing any addtional test blocks which may be required for weld repair qualification tests and casting weldability assessment. Test blocks shall be examined nondestructively in accordance with Section 8
29、. The examination procedures and acceptance criteria shall be those to be used for the castings themselves. Mechanical Testing Tensile Tests Two tensile tests per test block shall be carried out in accordance with BS EN 10002-1. The test specimens shall be taken from the %-thickness position, or oth
30、er position as specified by the Purchaser, and shall be a minimum of 50 mm from the side and end faces of the block. The minimum yield and tensile strengths of the specimens shall be as specified by the Supplier for the casting. The elongation shall be at least 22% based on 5.65$3,. Reduction in are
31、a shall be at least 45 % . Impact Tests From each test block two sets of three Charpy V-notch test specimens shall be taken, one set sub-surface and the other mid-thickness. In each case the specimens shall be located a minimum of 50 nun from the side and end faces of the block. Testing shall be in
32、accordance with BS EN 10045-1. Test results shall meet the following impact values: minimum average (of three specimens) = O. 1 x (YS) J at -40C (where (YS) is the specified minimum yield stress in N/mm2) minimum individual = 75% of minimum average. Previous page is blank 15 STD-EEMUA PUB NO L?b-ENG
33、L It998 M 57bb739 0001894 b8b If the average value of three impact tests is less than the specified minimum average, or if one individual value is less than the specified minimum, the Supplier shall carry out a re-test in accordance with one of the following alternative procedures. Re-heat treat the
34、 casting and repeat the test in accordance with the foregoing requirements and acceptance criteria. Take three additional test pieces from the same sample and location as the ones that previously failed, re-test and add the test results to those previously obtained to obtain a new average. The new a
35、verage value for the six tests shall not be less than the specified minimum average, and not more than one individual value of the six tests shall be less than the specified minimum value. a) b) 7.2.3 Fracture Toughness (CTOD) Tests Historical CTOD data from development and or production castings sh
36、all be supplied with the tender. Data shall be representative of the casting material and of any repair welds and their associated HAZs for each grade being offered. In the absence of such data, CTOD testing shall be performed in accordance with BS 7448. Acceptance criteria shall be in accordance wi
37、th Appendix A, A2.6 c) of this Specification. - 7.2.4 Metallographic Examination Metallographic examination shall be made of the sub-surface and core regions of the separately cast test block to confirm satisfactory heat treatment. 7.2.5 Failure to Meet Acceptance Criteria If the results of any of t
38、he mechanical tests specified above fail to comply with the requirements of this Specification, the Supplier shall establish the cause of failure. He may then, subject to the Purchasers approval, submit the casting together with the test samples to a further heat treatment after which test pieces fr
39、om the test blocks shall be submitted to all the specified tests. If it is considered that a heat treatment is required which involves repeat normalising or quenching and tempering, this shall not be permitted after repairs have been carried out. If the further tests fail to meet all of the requirem
40、ents of this Specification, the casting shall be rejected. 16 STD-EEMUA PUB NO L7b-ENGL 1998 57bb73Li 0003875 512 8. INSPECTION AND NON-DESTRUCTIVE TESTING 8.1 8.1.1 8.1.2 8.1.3 8.1.4 General Each casting shall be examined by visual, magnetic particle, ultrasonic and radiographic techniques. The Sup
41、plier shall submit detailed inspection and NDT procedures for approval by the Purchaser. Acceptance of each casting shall be based on satisfactory NDT of the casting (including weld repairs). Final NDT of any repairs required by this Specification shall be completed and accepted after final heat tre
42、atment. A detailed Inspection and Test Schedule, including all examinations to be carried out at various stages of manufacture, shall be submitted for Purchasers review, normally at the bid stage. All castings shall typically be examined as follows (the stages are not listed in any particular chrono
43、logical order): a after cleaning and fettling: visual and basic dimensional checks after quality heat treatment: full visual inspection (on all accessible internal and external surfaces), MPI and ultrasonics after defect excavation and prior to repair welding: visual inspection and MPI of excavation
44、 and local area only after repair welding, to the repair area including a 50 mm band around each repair: visual inspection, MPI and ultrasonics; radiography where required (see 8.7.1). O O Additionally, after fuial stress relief and the completion of any machining: full visual inspection, plus magne
45、tic particle inspection and ultrasonic testing of weld repairs including a 50 mm band around each weld repair. Each casting shall be divided into four zones for the purpose of conducting and evaluating NDT as defined below. 17 Table 1 Definition of NDT Zones IA Zone Definition of Zone C D Regions of
46、 High Criticality Weld ends 150 mm or 2% x ma. section thickness from the stub end, whichever is less, across the full section thickness. Regions of High Stress Concentration A band covering the complete radii of curvature at all changes in section, plus a further 50 mm covering the parallel portion
47、 of the section at either side of the radii. The depth of this region is as defined for the outer zone in BS 6208, section 4.2 and Figure 1. This zone shall include all trunnion faces on padears and any other region of the casting shown to be highly stressed as a result of finite element analysis. S
48、urface Regions other than A or B All other surface regions of the casting extending to a depth of 30 mm or one third of casting thickness as defined in BS 6208. Mid Zone Only As defined in BS 6208. 8.1.5 The Supplier shall prepare detailed drawings for each casting indicating the extent of each insp
49、ection zone of the casting. These zones shall be based upon detailed FEA and will be subject to review and approval by the Purchaser. 8.2 Personnel AI 1 personnel undertaking visual inspection and nondestructive testing of castings manufactured in accordance with the requirements of this Specification shall, as a minimum, be qualified and certified to PCN Level 2 in the relevant technique. The PCN requirements for the manual ultrasonic testing of castings are contained in Appendix B1 of the PCN publication General Requirements for the Quaificm-on and Certijcaton
