Q/BQB 600-2018 English PDF (QBQB600-2018)
Q/BQB 600-2018 English PDF (QBQB600-2018)
See Chinese contents: Q/BQB 600-2018
Q/BQB 600-2018: General technical requirements for steel plates
ENTERPRISE STANDARD OF
BAOSHAN IRON and STEEL CO., LTD.
Replacing Q/BQB 600-2013
General Technical Requirements for Steel Plates
ISSUED ON: JANUARY 15, 2018
IMPLEMENTED ON: APRIL 10, 2018
Issued by: BAOSHAN IRON and STEEL CO., LTD.
Table of Contents
Foreword ... 3
1 Scope ... 5
2 Normative References ... 5
3 Ordering Information ... 5
4 Smelting Method ... 6
5 State of Delivery ... 6
6 Thermal Treatment ... 7
7 Chemical Analysis ... 7
8 Appearance ... 8
9 Dimension, Appearance, Weight and Permissible Tolerance ... 9
10 Additional Requirements ... 11
11 Inspection and Testing ... 15
12 Acceptance Check ... 17
13 Rounding-off of Numerical Value ... 18
14 Signs ... 18
15 Inspection Documents ... 18
16 Others ... 19
Appendix A (normative) Weight Calculation Method and Additional Value of Thickness for Various Thickness Precisions in Theoretical Weight ... 20 Appendix B (informative) Steel Weldability ... 22
This Standard was drafted in accordance with the rules in GB/T 1.1-2009 Directives for Standardization - Part 1: Structure and Drafting of Standards.
The formulation of this Standard takes GB/T 709-2006, EN 10029-2010 and ASTM A6M-2017, and the practical situation of manufacture in Baoshan Iron and Steel as a reference.
This Standard serves as a replacement of Q/BQB 600-2013 General Technical Requirements for Steel Plates. In comparison with the previous standard, there are several main changes as follows:
---In Normative References, the reference of GB/T 14977-2008 is added; the year of issuance of GB/T 18253 and GB/T 2975 is added;
---The default mode of the surface state of non-heat-treated steel plate during delivery is clarified;
---The stipulation that appearance quality may implement in accordance with GB/T 14977 through negotiation is added;
---It is clarified that quenching includes offline quenching and online quenching; ---The permissible tolerance of length that is over 10,000 mm becomes more rigorous;
---The stipulation of permissible tolerance of unevenness of untrimmed steel plate is added;
---The common unevenness precision tolerance of steel plate whose width is more than 3,000 mm becomes more rigorous;
---In the rounding-off of numerical value, it is clarified that the determination of numerical value adopts rounded-off value comparison method.
In this Standard, Appendix A is normative; Appendix B is informative.
This Standard was proposed by the Manufacturing Management Department of Baoshan Iron and Steel Co., Ltd.
This Standard shall be under the jurisdiction of the Manufacturing Management Department of Baoshan Iron and Steel Co., Ltd.
This Standard was drafted by the Manufacturing Management Department of Baoshan Iron and Steel Co., Ltd.
General Technical Requirements for Steel Plates
1.1 This Standard stipulates a group of general technical requirements for thick steel plates. The content includes ordering information, smelting method, state of delivery, thermal treatment, chemical analysis, surface, dimensions, appearance, weight, additional requirements, inspection and testing, acceptance check, rounding-off of numerical values, signs and inspection documents, etc.
1.2 This Standard is applicable to thick steel plates (hereinafter referred to as steel plates) manufactured by Baoshan Iron and Steel Co., Ltd.
1.3 When product standards or contract stipulations are inconsistent with the stipulations in this Standard, product standards and contract stipulations shall prevail. 2 Normative References
The following documents are indispensable to the application of this Standard. In terms of references with a specified date, only versions with a specified date are applicable to this Standard. In terms of references without a specified date, the latest version (including all the modifications) is applicable to this Standard.
GB/T 222 Permissible Tolerances for Chemical Composition of Steel Products GB/T 8170 Rules of Rounding-off For Numerical Values and Expression and
Judgement of Limiting Values
GB/T 14977-2008 General Requirement for Surface Condition of Hot-rolled Steel Plates
GB/T 18253-2000 Steel and Steel Products - Types of Inspection Documents GB/T 2975-1998 Steel and Steel Products - Location and Preparation of Test Pieces for Mechanical Testing
3 Ordering Information
3.1 In accordance with demands, during ordering, users need to provide the following information that is sufficient to illustrate necessary documents:
a) Standard No. and nameplates;
b) Specifications, tolerances and weights;
c) The state of edges, the state of delivery and the state of surface;
d) Purposes, and types of inspection documents;
e) Others (such as additional requirements, requirements of weld repairs). 3.2 When the grade of thickness tolerances, the state of edges and the grade of unevenness tolerances are not stated in the order contract, products shall be delivered in accordance with the grade of thickness tolerances - PT.N, the state of edges - EC, and the grade of common unevenness precision PF.N. When the state of delivery is not stated, the supply-side shall determine. In terms of non-heat-treated steel plates, when the surface state is not stated, products shall be delivered in the state of black surface. When the type of inspection documents is not appointed, comply with Type 5.1 B in GB/T 18253-2000.
NOTE: the type of inspection documents: Type 5.1 B in GB/T 18253-2000 is equivalent to Type 3.1 in EN 10204-2004.
4 Smelting Method
Steel shall be killed steel smelted through oxygen converter or electric furnace. 5 State of Delivery
5.1 Steel plates may be delivered in the state of rolling, normalized rolling, thermo- mechanical controlled rolling and/or thermal treatment, unless it is otherwise stipulated in product standards or contracts.
5.2 When the delivery state of steel plates is not stipulated in product standards or contracts, the supply-side shall determine.
5.3 The classification and code of the delivery state of steel plates is shown in Table 1. c) Before welding and repairing, adopt appropriate methods, such as evening out or polishing to completely remove detrimental defects on steel plates. The depth of the removed parts shall be within 20% of the nominal thickness of steel plates. The total of a single-sided grinded area shall be within 2% of the area of steel plates.
d) On the edges of steel plates?€? welded parts, there shall be no undercuts or overlaps. Stack height shall be more than 1.5 mm higher than the rolled surface; then, use methods like evening out or polishing to remove the stack height. e) In terms of heat-treated steel plates, after welding and repairing, they shall receive thermal treatment again.
f) The welding and repairing of products whose minimum tensile strength is stipulated to be not less than 690 MPa shall be negotiated through the demand- side and the supply-side.
8.2.2 If the demand-side demands, through the negotiation between the demand-side and the supply-side, and indication in the contract, surface quality may implement in accordance with GB/T 14977. Under this circumstance, if classification or grade is not indicated in the contract, comply with Class-B, Grade-1 requirements in GB/T 14977. 9 Dimension, Appearance, Weight and Permissible
9.1 Classification and Code
9.1.1 In accordance with the state of edges, steel plates shall be divided into: Trimmed: EC
9.1.2 In accordance with the grade of thickness tolerance, steel plates shall be divided into:
PT.N: symmetrical tolerance;
PT.A: negative tolerance is stipulated in accordance with nominal thickness; PT.B: asymmetric tolerance whose negative tolerance is 0.30 mm;
PT.C: fixed negative tolerance is 0; positive tolerance is stipulated by nominal thickness. 9.1.3 In accordance with the grade of unevenness tolerance, steel plates shall be divided into:
9.4.4 Untrimmed steel plates?€? out-of-squareness
22.214.171.124 Steel plates?€? out-of-squareness (u) may adopt projection method in measurement, or, it may also adopt diagonal method in measurement. When projection method is adopted in measurement, the measured out-of-squareness (oblique cutting) u shall be not more than 1% of the actual width of steel plates. When diagonal method is adopted in measurement, the out-of-squareness (u), which is obtained through calculation, shall be not more than 0.7% of the actual width of steel plates.
126.96.36.199 When there is any dispute, the projection method measurement shall be adopted for arbitration.
9.4.5 In terms of untrimmed steel plates?€? camber and out-of-squareness, if the demand-side has demands, the demand-side and the supply-side may negotiate and determine them during ordering.
When steel plates are delivered in accordance with theoretical weight, the thickness adopted in theoretical weight is the average value of the maximum allowable thickness and the minimum allowable thickness (in other words, nominal thickness plus the additional value of thickness); width and length shall adopt the nominal dimensional value. Unless it is otherwise stipulated in product standards, steel?€?s density shall adopt 7.85 g/cm3 (in other words, the basic weight is 7.85 kg/(mm.m2)). Please refer to Appendix A (normative) for the calculation method for the theoretical weight and the additional value of thickness for various thickness precisions.
In accordance with the demand-side?€?s demands, through the negotiation between the demand-side and the supply-side, and indication in the contract, dimension, appearance, weight and permissible tolerance may be otherwise stipulated. 10 Additional Requirements
In accordance with the demand-side?€?s demands, through the negotiation between the demand-side and the supply-side, and indication in the contract, other inspection items, such as analysis of finished products, mechanical test, process test, metallographic examination, non-destructive testing (ultrasonic flaw detection UT, magnetic particle inspection MT, penetrant flaw detection PT) and welding test may be supplemented. qualified, then, the whole batch shall be deemed as qualified. Even if one of the indicators is disqualified in the re-inspection result (including all the indicators requested in the item), then, the whole batch shall be deemed as disqualified. 12.4 Re-classification and rework
Before or after re-inspection, disqualified steel plates may receive re-classification and rework. Please see the specific methods as follows:
a) Single-piece of steel plate which already receives the inspection and is disqualified in the inspection result shall not be accepted. However, steel plates that do not receive the inspection in the batch may be re-submitted piece by piece for inspection and acceptance check.
b) Disqualified steel plates shall re-receive thermal treatment, then, be re-grouped and submitted for inspection and acceptance check.
13 Rounding-off of Numerical Value
The determination of numerical value shall adopt rounded-off value comparison method. Rounding-off of numerical value shall comply with the stipulations in GB/T 8170.
14.1 Steel plates?€? signs shall be distinct.
14.2 Generally speaking, steel plates shall be delivered piece by piece. Each piece of steel plate shall spray-print or engrave certain signs, such as the supply-side?€?s trademark, standard No., nameplate, furnace No., dimensions, steel plate No., weight, and symbols of special requirements.
15 Inspection Documents
15.1 Each batch of steel plates being delivered must issue inspection documents. In accordance with demands, inspection documents shall indicate: the supply-side?€?s name and trademark, product-ordering and product-receiving organization, contract No., product name, standard No., nameplate, delivery state, dimensions and specifications, furnace No., steel plate No., delivery weight, various test results stipulated in the standards, date of issuance, signature of the principal of quality management department.
15.2 The type of inspection documents shall comply with the stipulations in GB/T 18253.
B.1 Steel?€?s weldability refers to the relative difficulty of steel being shaped through welding under the traditional welding methods (manual arc welding, submerged arc welding, melting gas shielded welding, non-melting gas shielded welding, electric resistance welding, plasma arc welding, electron beam welding and laser welding). B.2 During the welding thermal cycle process of steel, in welded joints and base metal, certain brittle and unfavorable organizational structure might be generated, which leads to brittle cracking of welded joints and base metal. In terms of steel, the primary welding question is cold crack.
B.3 Generally speaking, steel?€?s cold crack sensitivity is known as hardenability. Hardenability may be determined through many methods. The most common method is carbon equivalent method.
B.4 In steel, carbon is the primary hardening element. The calculation of carbon equivalent is to convert the influence of carbon content and main alloy elements in steel (such as manganese and vanadium) on hardenability into corresponding carbon content, then, accumulate it.
B.5 The most commonly used carbon equivalent formula is the carbon equivalent formula by International Institute of Welding. It has been proved by a lot of production practices that it is applicable to the majority of commonly used carbon manganese steel and low-alloy steel.
The following is the method for the calculation of carbon equivalent. Where, the mass percentage of chemical composition is based on the result of smelting analysis. B.6 In terms of low-carbon steel and low-alloy steel, when steel is mainly reinforced through the means of microalloying and thermal treatment, other formulas may also be adopted to more-accurately determine steel?€?s hardenability and cold crack sensitivity. B.7 In terms of steel for most common structures, it is unnecessary to stipulate the maximum limit of carbon equivalent. However, under certain specific circumstances, users may stipulate the maximum value of carbon equivalent.
B.8 In the selection of appropriate carbon equivalent, users shall consider the following