1、Specification for Mooring ChainANSI/API SPECIFICATION 2FSIXTH EDITION, JUNE 1997REAFFIRMED, JUNE 2015Specification for Mooring ChainUpstream SegmentANSI/API SPECIFICATION 2FSIXTH EDITION, JUNE 1997REAFFIRMED, JUNE 2015SPECIAL NOTESAPI publications necessarily address problems of a general nature. Wi
2、th respect to partic-ular circumstances, local, state, and federal laws and regulations should be reviewed.API is not undertaking to meet the duties of employers, manufacturers, or suppliers towarn and properly train and equip their employees, and others exposed, concerning healthand safety risks an
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13、pyright 1997 American Petroleum InstituteiiiFOREWORDAPI publications may be used by anyone desiring to do so. Every effort has been made bythe Institute to assure the accuracy and reliability of the data contained in them; however, theInstitute makes no representation, warranty, or guarantee in conn
14、ection with this publicationand hereby expressly disclaims any liability or responsibility for loss or damage resultingfrom its use or for the violation of any federal, state, or municipal regulation with which thispublication may conflict.Suggested revisions are invited and should be submitted to t
15、he director of the Explorationand Production Department, American Petroleum Institute, 1220 L Street, N.W., Washing-ton, D.C. 20005-4070.CONTENTSPage1 SCOPE. 12 REFERENCES 13 BAR STOCK REQUIREMENTS AND TESTS . 14 CHAIN REQUIREMENTS AND TESTS 35 KENTER LINK REQUIREMENTS AND TESTS 8Figures1Tensile Tes
16、t Specimen 22Orientation of Charpy V-Notch Impact Test Specimens . 23Basic Link and Stud Weldment 44Kenter Link Critical Dimensions. 95Critical Shapes to Be Mated With API Kenter Link . 11Tables1Chemical Composition Ladle Analysis . 12Mechanical Properties 23Dimensional Tolerance of Bar Stock. 24Fre
17、quency of Tests . 35Dimensions and Tolerances . 46Mooring Chain Proof and Break Tests, Length Over Five Links, andApproximate Weight (Customary Units) 57Mooring Chain Proof and Break Tests, Length Over Five Links, andApproximate Weight (SI Units). 68Kenter Link Dimensions and Tolerances. 10vCONTENTS
18、Page1Specification for Mooring Chain1 ScopeThis specification covers flash-welded chain and forgedkenter connecting links used for mooring of offshore floatingvessels such as drilling vessels, pipe lay barges, derrickbarges, and storage tankers.2 ReferencesThe most recent editions or revisions of th
19、e following stan-dards are referenced in this publication:ASTM1A 370Mechanical Testing of Steel ProductsE 309-95Eddy-Current Examination of Steel TubularProducts Using Magnetic SaturationE 709Magnetic Particle ExaminationE 1444Magnetic Particle InspectionDNVCertification Notes 2.6, July 1985ISO R286
20、-1962 Code H11, h113 Bar Stock Requirements and Tests3.1 STEEL MAKING PROCESSThe steel used for the manufacture of chain shall be madeby the open hearth, basic oxygen, or electric furnace process.3.2 CHEMICAL COMPOSITIONAll material shall be of fine grain quality. The chemicalcomposition shall be de
21、termined at the steel mill on samplestaken from each ladle of each heat and shall comply with thecomposition shown in Table 1. A copy of the mill sheet listingthe chemical composition of each heat shall be provided tothe owners representative. If the material fails to satisfy thechemical composition
22、 requirements in Table 1, the materialshall be rejected.3.3 MECHANICAL PROPERTIESThe bar stock used in the manufacture of chain furnished tothis specification shall possess the mechanical propertiesshown in Table 2. These properties shall be determined ateither the steel mill or the manufacturing fa
23、cility in the man-ner described below. Results shall be certified by a recognizedtesting agency and submitted to the owners representative.3.4 TENSILE TESTSOne tensile test shall be made on each heat of steel.Note: When more than one test specimen for each heat is required to be incompliance with cl
24、assification-society rules, the frequency of removing testspecimens is to be based on classification rules.Tensile properties shall be determined on a longitudinalspecimen conforming to the requirements of 3.5. The resultsof the test shall meet or exceed the minimum requirementslisted in Table 2. If
25、 the original test fails to meet the require-ments in Table 2 but are within 2000 pounds per square inch(14 megapascals) of the required tensile strength, or within 2percent of the required elongation, a retest of another speci-men selected from the same heat is permissible. If the secondtest fails
26、to meet the requirements of Table 2 the material shallbe rejected.3.5 TENSILE TEST SPECIMENSThe tensile specimen shall be taken from bar stock whichhas been subjected to the same heat treatment as that speci-fied for the finished chain. Tensile test specimens may beeither full bar diameter or machin
27、ed specimens as shown inFigure 1, at the option of the manufacturer. For test specimenswith diameters smaller than the full bar diameter, the positionof the test specimen relative to the bar cross section shall beselected so that the specimen is representative of the averageproperties of the bar.3.6
28、 IMPACT TESTSThree impact tests shall be made on each heat of steel.Note: When more than three test specimens for each heat are required to bein compliance with classification-society rules, the frequency of removingtest specimens is to be based on classification rules.Impact properties shall be det
29、ermined on specimens con-forming to the requirements of 3.7. The average results of thethree tests shall meet or exceed the minimum requirementsTable 1Chemical Composition Ladle AnalysisElement Percent Minimum MaximumCarbon, C 0.33Silicon, Si 0.200.35Manganese, Mn 1.90Phosphorus, P 0.04Sulphur, S 0.
30、04Nitrogen, N 0.015Chromium, Cr 0.25Copper, Cu 0.35Columbium, Cb (Niobium, Nb)a0.05Nickel, Ni 0.40Vanadium, Va0.10Aluminum, Ala0.065Molybdenum, Mo 0.08aTo obtain fine grain steel, at least one of these grain refining elements in suf-ficient amount(s) must be present to meet the fine grain practices
31、per 3.2.1American Society for Testing and Materials, 100 Bar Harbor Drive, WestConshohocken, Pennsylvania 19428.2 API SPECIFICATION2Flisted in Table 2. If the average fails to meet the minimumrequirement by an amount not exceeding 15 percent, threeadditional specimens from the same bar stock may be
32、testedand the results added to those previously obtained to form anew average. If the new average fails to meet the require-ments of Table 2, the material shall be rejected. No individualCharpy values shall be less than 75 percent of the averageminimum requirement.3.7 IMPACT TEST SPECIMENSImpact tes
33、t specimens shall be taken from bar stock whichhas been subjected to the same heat treatment as that speci-fied for the finished chain. Impact test specimens shall beCharpy V-notch as described in ASTM A 370. General orien-tation of the specimens shall be as shown in Figure 2.3.8 DIMENSIONAL TOLERAN
34、CE AND REQUIREDINSPECTIONThe diameter tolerance on bar stock used in the manu-facture of chain furnished to this specification shall be asshown in Table 3. One hundred percent of the bar stockshall be examined by magnetic particle inspection perASTM E 709 and ASTM E 1444 or eddy-current inspec-tion,
35、 ASTM E 309.Table 2Mechanical PropertiesTested Properties RequirementsUltimate strength, minimum 93,000 pounds per square inch(641 megapascals)Elongation, minimuma17 percentReduction in area, minimum 40 percentImpact, averageBar stock and unwelded portion of link 43 foot-pounds 32F(58 Joules 0C)Flas
36、h weld zone 36 foot-pounds 32F(49 Joules 0C)Impact, average for low-temperatureapplicationUnwelded portion of link 29.5 foot-pounds 5F(40 Joules -15C)Flash weld zone 26.5 foot-pounds 5F(36 Joules -15C)aThe minimum elongation of 17% is based on a specimen having gauge length equal to five times the d
37、iameter of the specimen. For specimens having other gauge lengths, the equivalent elongation may be calculated by the following formula:n = Where:n = the equivalent minimum elongation, %.A = the actual cross-sectional area of the specimen, inch2(millimeter2).L = the actual gauge length, inch (millim
38、eter).E = the specified minimum percentage elongation for specimens havinga gauge length of five times the specimen diameter, %.2EAL-0.4Reduced section2.75 in. min.(70 mm min.)2.5 in. 0.005 in.(63.5 mm 0.13 mm)Gauge length for measuringelongation after fractureRadius0.5 in. min.(13 mm min.)0.500 in.
39、 0.005 in.(12.7 mm 0.13 mm)Note: The gauge length and fillets shall be as shown, but the ends may be of any shape to fit the holders of the testing machine in such a way that the load shall be axial. The reduced section may have a gradual taper from the ends toward the center, with the ends not more
40、 than 0.005 inch larger in diameter than the center.Figure 1Tensile Test SpecimenNotchr23rFigure 2Orientation of Charpy V-NotchImpact Test SpecimensTable 3Dimensional Tolerance of Bar StockMaximumNominal Nominal Depth ofSize of Size of LongitudinalBar Stock Tolerance Bar Stock Tolerance Defects(inch
41、es) (inches) (millimeters) (millimeters) (millimeters)Up to 138 +132 0 Up to 34 +1.2 0 0.40112 to 2 +116 0 34 to 50 +1.6 0 0.50218 to 318 +332 0 51 to 80 +2.0 0 0.80314 to 4 +332 0 81 to 100 +2.6 0 1.00418 to 434 +18 0 101 to 120 +3.0 0 1.20478 to 638 +532 0 121 to 160 +4.0 0 1% of d612 to 778 +316
42、0 161 to 200 +5.0 0 1% of dSPECIFICATION FOR MOORINGCHAIN34 Chain Requirements and Tests4.1 IDENTIFICATION OF TEST LINKSChain shall be manufactured in continuous lengths. Foridentification during manufacture, each length of chain shouldbe marked with a metal band strapped around the stud of thesecon
43、d link from either end of the total length. The lengthnumber shall be stamped on the metal band. No numbershould be duplicated.4.2 TEST SPECIMENDuring manufacture, a specimen consisting of at least fourlinks shall be taken from the chain in accordance with Table 4to provide the test specimen for bre
44、ak tests and mechanicalproperty measurements. After removal of the specimen fromthe chain, the specimen shall be identified with a metal bandplaced around the stud of one of the links. The identificationshall include the order number, the chain length number, andthe test specimen number (for example
45、, 2-2-3 could denotethe second order, the second length of chain, and the thirdspecimen removed from the second length of chain). A metalband with the same marking shall be placed around the studof the last link in the continuous portion of the chain todenote the location where the specimen was remo
46、ved. Afterremoval of the specimen, manufacture of the chain shallresume with a new common link being inserted into the lastlink of the continuous chain length previously constructed.4.3 MARKING FOR PERMANENT IDENTIFICATIONThe common links marked with metal bands shall bemarked for permanent identifi
47、cation using the same numberingsystem described above. Markings shall be on the stud and maybe accomplished by a forging stamp or weld metal deposit.4.4 CHAIN STUDThe studs shall be drop-forged and shall not have lugs orprotrusions on either end. After the stud is inserted into theoval link, unless
48、otherwise agreed, it shall be circumferen-tially welded in place on the end opposite the flash weld. Thesize of the fillet weld will comply with the data shown in Fig-ure 3 and Table 5. Only low-hydrogen electrodes shall beused, and the welds are to have good penetration with a maxi-mum undercut not
49、 to exceed 132inch (1 millimeter). All weld-ing shall be performed prior to the final heat treatment. Studsand chain shall meet the same material chemical specificationper Table 1.4.5 HEAT TREATMENT OF COMPLETED CHAINThe chain shall be normalized, normalized and tempered,or quenched and tempered to produce a fine grain structurethroughout the links weld and fusion zone. All chain is to beheat-treated by continuous processing; batch heat treatment isnot permitted. Heat treatment shall be performe
