Q/BQB 616—2018 Q/BQB 616－2018 Supersedes BZJ 611－2013 EnglishVersion High strength steel plates for welded structure Q/BQB616—2018 I Foreword This standard is drafted in accordance with therules given in the GB/T 1.1—2009 (Directives forstandardization-Part1: Structure and drafting of standards). Thisstandard is drafted according to the market demand, considering thepractical condition in Baosteel. This standard replaces BZJ611－2013 " High strength steel plates for welded structure ". Inaddition to a number of editorial changes, the following technicaldeviations have been made with respects to the BZJ 611－2013 (theprevious edition). ——Add references GB/T 20124 and GB/T 20125, thedated of GB/T 2975 in normative references; ——Extend the thicknessrange of some steel grades, and add the chemical composition andproperty correspondingly; ——Add grades BWELDY620QL2, BWELDY620QL4and BWELDY620QL6, and corresponding technical requirements; ——Addthe specification for higher accuracy of flatness; ——Tighten therequirement for the content of Mo, V and Ceq for all grades; ——Addthe specification that if the performance of bending test can beguaranteed, the bending test may be omitted; ——Tighten thespecification of impact property; ——Add the specification that ifwelding repairing is needed, this shall be agreed between themanufacturer and the purchaser; ——Clarify the sampling position oftensile test pieces and impact test pieces; ——Improved thespecification of sampling and retesting for the test unit of impacttest. This standard was jointly proposed by ManufacturingManagement Department. This standard was jointly prepared byManufacturing Management Department. This standard is under thejurisdiction of Manufacturing Management Department,this standardis the direct responsibility of Manufacturing ManagementDepartment. This standard was drafted by: Huang jinhua. Thisedition has been approved on Jan.15, 2018, and validated on Apr.10,2018. The Chinese text of this standard shall be deemed theoriginal. The English version is only for information. In the eventof any dispute or misunderstanding as to the interpretation of thelanguage or terms of this specification, the Chinese languageversion shall be prevail. Q/BQB 616—2018 1 High strength steelplates for welded structure 1 Scope This standard specifiesdimensions, shape, technical requirements, testing and inspection,marking, and inspection certificate of high strength thick steelplates for welded structure. This standard is applicable to thehigh strength thick steel plates for welded structure manufacturedby BAOSTEEL. 2 Normative references The following referenceddocuments are indispensable for the application of this document.For dated references, only the edition cited applies. For undatedreferences, the latest edition of the referenced document(including any amendments) applies. GB/T 223 Methods for chemicalanalysis of iron, steel and alloy GB/T 228.1 Metallicmaterials–Tensile testing–Part 1: Method of test at roomtemperature GB/T 229 Metallic materials–Charpy pendulum impact testGB/T 232 Metallic materials–Bend test GB/T 2970 Method forultrasonic testing of thicker steel plates GB/T 2975-1998 Steel andSteel Products--Location and preparation of test pieces formechanical testing GB/T 4336 Carbon and Low-Alloy Steel -Determination of Multi-Element Contents - Spark discharge atomicemission spectrometric method (Routine Method) GB/T 20066-2006Steel and Iron: Sampling and preparation of samples for thedetermination of chemical composition GB/T 20123 Steel and Iron -Determination of total carbon and sulfur content infraredabsorption method after combustion in an induction furnace (RoutineMethod) GB/T 20124 Steel and Iron - Determination of nitrogencontent thermal conductimetric method after fusion in a current ofinert gas (Routine Method) GB/T 20125 Low-Alloy Steel -Determination of multi-element contents - inductively coupledplasma atomic emission spectrometric method Q/BQB 600 Generaltechnical requirements for steel plate 3 General technicalrequirements Unless other specifications have been shown in thisstandard, the steel plate delivered by this standard shall complywith the corresponding requirements of Q/BQB 600. 4 Classificationand Code 4.1 The steel grade, the nominal thickness, and theapplication of steel plate are shown in Table 1. Table 1 Steelgrade Nominal thickness mm Application BWELDY620QL2, BWELDY620QL4 ,BWELDY620QL6 BWELDY700QL2 , BWELDY700QL4 8 to 100 Used forexcavators, forklifts, concrete pump trucks, truck cranes and otherconstruction machinery that require good welding performance andcomprehensive mechanical properties, as well as the hydraulicsupports of coal mining machinery, large cranes and other mines,port machinery structures. BWELDY900QL2 , BWELDY900QL4 BWELDY960QL2, BWELDY960QL4 10 to 60 4.2 The higher flatness accuracy of steelplate, PF.S, is classified as two levels, PF.S1 and PF.S2. Q/BQB616—2018 2 5 Dimensions, shapes, mass The higher flatness accuracylevels PF.S1 and PF.S2 of trimmed edge steel plates shall conformto Table 2. Other requirements of dimensions, shapes, mass, andpermissible tolerance shall conform to Q/BQB 600. Table 2Measurements in length Tolerances for different levels of higherflatness accuracy not greater than PF.S1 PF.S2 1000 mm 7 mm 5 mm 6Technical requirements 6.1 Steel grade and chemical composition Thesteel grade and the chemical composition (heat analysis) shallcomply with the requirement in Table 3. Table 3 6.2 Deliverycondition Steel plates are delivered in the quenched and temperedcondition. 6.3 Mechanical property and processing performance 6.3.1The mechanical properties and processing performance of steel plateshall comply with the requirement in Table 4. 6.3.2 After bendingtest, the outer surface of the test piece shall be free fromvisible cracks. If the performance of bending test can beguaranteed by the manufacturer , the bending test may be omitted.6.3.3 The value of Charpy absorption energy shall be taken from theaverage of three test pieces. It is acceptable that one out ofthree test values is lower than the specified value but not lessthan 70% of the specified value. 6.3.4 Charpy impact test is onlyapplicable to the steel plate with thickness not less than 6 mm.When the impact test is made on the steel plate with thickness notless than 12 mm, the standard test specimen of Steel grade Chemicalcomposition a （heat analysis） % C ≤ Si ≤ Mn≤ P ≤ S ≤ Nb ≤ Ti ≤ V ≤Alt ≥ Others Ceq b Thickness mm ≤50 ＞50 BWELDY620QL2 BWELDY700QL20.18 0.50 1.60 0.025 0.015 0.05 0.05 0.05 0.020 Cr ≤0.80 Mo≤0.60 Ni≤2.00 Cu ≤0.30 B ≤0.005 N ≤0.015 ≤ 0.57 ≤ 0.62 BWELDY620QL4BWELDY620QL6 BWELDY700QL4 0.020 0.010 BWELDY900QL2 0.20 0.50 1.700.025 0.015 0.05 0.05 0.05 0.020 ≤ 0.62 ≤ BWELDY900QL4 0.020 0.0100.67 BWELDY960QL2 0.20 0.50 1.70 0.025 0.015 0.05 0.05 0.05 0.020 ≤0.65 ≤ BWELDY960QL4 0.020 0.010 0.70 a Other alloying elements maybe added when needed. b Ceq = C + Mn / 6 + (Cr + Mo + V) / 5 + (Ni+ Cu) / 15。 Q/BQB 616—2018 3 10.0 mm×10.0 mm×55 mm shall be used,and the test result shall comply with the specified value in thetable; when the impact test is carried out on steel plate withthickness not less than 6 mm but less than 12.0 mm, the auxiliarytest pieces of 7.5 mm×10.0 mm×55 mm or 5.0 mm×10.0 mm×55 mm shallbe applied, and the test result shall not be less than 75% or 50%of the specified value given in the table, respectively. 6.3.5 Ifthe result of Charpy impact test does not meet the specifiedrequirements, three other test pieces may be taken on the samesampled product for testing. At this time, the average value ofthese six test pieces should not be less than the specified value.No more than two out of six values are allowed to be less than thespecified value, and only one value is allowed to be less than 70%of the specified value. Table 4 Steel grade Tensile test Impacttest b 180°bend test c b = 2a （a = thickness of test piece, b =width of test piece, D－diameter of the former end） Upper yieldStrength a MPa Tensile strength MPa Elongation after fracture, %,（L0 = S0 5.65 ） Temperature ℃ Charpy absorption energy KV2 JThickness mm Thickness mm ≤50 ＞50 ≤50 ＞50 BWELDY620QL2 ≥620 ≥600700 to 890 700 to 890 ≥15 -20℃ ≥47 BWELDY620QL4 -40℃ ≥34 D = 3aBWELDY620QL6 -60℃ ≥34 BWELDY700QL2 ≥700 ≥670 770 to 940 760 to 930≥14 -20℃ ≥47 D = 3a BWELDY700QL4 -40℃ ≥34 BWELDY900QL2 ≥900 ≥850940 to 1150 890 to 1150 ≥12 -20℃ ≥34 D = 3a BWELDY900QL4 -40℃ ≥34BWELDY960QL2 ≥960 ≥910 980 to 1150 930 to 1150 ≥12 -20℃ ≥34 D = 3aBWELDY960QL4 -40℃ ≥34 a The test piece taken transversely isapplied to tensile test; when definite yield phenomenon is notpresent, the yield strength values apply to the Rp0.2. b The testpiece taken longitudinally is applied to tensile test, and theCharpy test piece is the standard test piece. C The test piecetaken transversely is applied to bend test. 6.4 Surface quality Ifwelding repairing is necessary, it shall be agreed between themanufacturer and the purchaser and indicated in the order. Otherrequirements of surface quality shall conform to Q/BQB 600. 6.5Ultrasonic test If required by the purchaser, upon the agreementbetween the manufacturer and the purchaser indicated in the order,ultrasonic test may be performed on each plate individually. Theultrasonic test method shall comply with GB/T 2970, and theaccepted level shall be indicated in the order. 7 Inspection andtesting 7.1 When selecting the specified inspection and test, thetype of inspection document shall comply with the requirement of6.2 to 6.4. 7.2 The number of test pieces, the sampling method andthe test method required by the inspection items for each test unitof steel plate shall comply with the requirements in Table 5. Q/BQB616—2018 4 Table 5 No. Inspection item Number of test pieceSampling method b Test method 1 Chemical analysis a 1 per heat GB/T20066 GB/T 223 , GB/T 4336 , GB/T 20123 , GB/T 20124 or generalmethod 2 Tensile test 1 When thickness≤25mm, GB/T 2975 Figure A10 a(full thickness plate type) Thickness＞25mm to ≤50mm, GB/T 2975Figure A10 a or d Thickness＞50mm, GB/T 2975 Figure A10 d（1/4t bartype） GB/T 228.1 3 Bend test 1 GB/T 2975 GB/T 232 4 Impact test 1set (3 pieces) Thickness ≤40mm, GB/T 2975 Figure A11 a（near tosurface） Thickness ＞40mm, GB/T 2975 Figure A11 b（1/4t） GB/T 229 5Ultrasonic test （agreed） Each plate - GB/T 2970 a At the time ofarbitration, the test method shall comply with GB/T 223. b Thesample is allowed to be shearing or flame cutting, but the size ofthe sample must be appropriate to enable the sample to be away fromthe hardened or heat affected zone caused by shearing or flamecutting. The sampling position shall be as close as possible to thespecified positions when sampling at those exact positions is notfeasible. 7.3 Sampling frequency 7.3.1 Sampling frequency forchemical analysis Heat analysis shall be adopted for the chemicalanalysis to each heat individually. 7.3.2 Sampling frequency formechanical properties and processing performance Each test unitshall consist of steel plates which the maximum mass is 40 tons,plates have the same heat number, the same grade, and the sametensile strength which regular , the difference between the maximumand the minimum thickness is not greater than 5 mm. The impact testpiece shall be taken from the thickest steel plate in the testunit. 7.3.3 Upon the agreement between the manufacturer and thepurchaser, the rule for setting test unit may be additionallydetermined. 7.4 Re-test of impact test If the result of impact testdo not meet the specified requirement, the tested but failed platecannot be accepted; however, the other steel plates with the samethickness as the sampled product shall be subjected to impact testand accepted individually. The steel plate with other thicknessesshall be set as a new test unit and submitted for the impact testand acceptance.