Q/BQB 416-2009 English PDF (QBQB416-2009)
Q/BQB 416-2009 English PDF (QBQB416-2009)
See Chinese contents: Q/BQB 416-2009
Q/BQB 416-2009: Baking hardening high-strength cold rolled steel plate and strip
ENTERPRISE STANDARD OF
BAOSHAN IRON AND STEEL CO., LTD
Replacing Q/BQB 416-2003
Baking hardening high-strength cold rolled steel plate
Issued on: January 08, 2018 Implemented before: June 30, 2008
Baoshan Iron and Steel Co., Ltd.
Table of Contents
1 Scope ... 3
2 Normative references ... 3
3 Terms and definitions ... 4
4 Classification and code ... 4
5 Information required for ordering ... 5
6 Dimensions, shape, weight and allowable deviation ... 6
7 Technical Requirements ... 6
8 Inspection and test ... 9
9 Packaging, marking and inspection documents ... 10
10 Rules of rounding off of numerical values ... 10
11 Approximate comparison of domestic and foreign designations ... 10
Appendix A (Normative) Measuring method of baking hardening value (BH2) 11 Appendix B (Informative) Approximate comparison between this standard
designation and domestic and foreign standard designations ... 13
Baking hardening high-strength cold rolled steel
plate and strip
This Standard specifies the terms and definitions, classification and code, dimensions, shape, weight, technical requirements, inspection and test, packaging, marking and inspection documents of baking hardening high-strength cold rolled steel plate and strip.
This Standard applies to baking hardening high-strength cold rolled steel plate and strip (hereinafter referred to as steel and strip) whose thickness is 0.50 mm ~ 2.5 mm, which is produced by Baoshan Iron and Steel Co., Ltd.
2 Normative references
The terms in the following documents become the terms of this Standard by reference to this Standard. For dated references, all subsequent amendments (not including errata content) or revisions do not apply to this standard. However, parties to agreements that are based on this Standard are encouraged to study whether the latest versions of these documents can be used. For undated references, the latest edition applies to this Standard.
GB/T 222-2006 Permissible tolerances for chemical composition of steel
GB/T 223 Methods for chemical analysis of iron, steel and alloy
GB/T 228-2002 Metallic materials - Tensile testing at ambient temperature GB/T 2523-2008 Measuring method of surface roughness and peak count for cold-rolled metal sheet (strip)
GB/T 2975-1998 Steel and steel products - Location and preparation of test pieces for mechanical testing
GB/T 4336-2002 Carbon and low-alloy steel. Spark discharge atomic emission spectrometric method (routine method)
GB/T 5027-2007 Metallic materials - Sheet and strip - Determination of plastic BH2 value tests, if one of the test results does not meet the standard requirements, then, take double the number of samples from the same batch and perform a repeated test of the unqualified item. If the retest results (including all indicators that are required for the item test) are qualified, judge the entire batch to be qualified. Even if one indicator of the retest results (including all indicators that are required for the item test) is unqualified, judge the retest to be unqualified. If the retest is unqualified, the unit that has been tested, of which the test results are unqualified, cannot accepted; but the unit that has not been tested in the batch of materials can be resubmitted to a retest and accepted one by one.
9 Packaging, marking and inspection documents
The packaging, marking and inspection documents of the plate and strip shall comply with the requirements of Q/BQB 400. If the buyer has special requirements for the weight of the package, it shall be specified in the contract.
10 Rules of rounding off of numerical values
The rules of rounding off of numerical values shall be in accordance with the provisions of GB/T 8170.
11 Approximate comparison of domestic and foreign
The approximate comparison between this standard designation and domestic and foreign standard designations is shown in Appendix B.
Measuring method of baking hardening value (BH2)
The dimensions and sampling direction of the sample shall be in accordance with the requirements of the mechanical property sample.
A.2 Test conditions
When measuring the baking hardening value, according to the provisions of GB/T 228, firstly perform the pre-stretching of 2% of the total elongation of the sample; at the same time, measure Rt2.0. When the pre-stretched 2% sample has completed the prescribed heat treatment, perform a tensile test of the sample again, to measure ReL or Rp0.2.
In order to better maintain the consistency of the test results, it should use a displacement or strain method to control the stretching speed; it is recommended to set the stretching speed at a rate of 5%/min of the parallel length of the sample; from the beginning of the stretching to the above indicators are measured, do not switch speed.
Rt2 = Ft2.0/A0
Rp0.2 = Fp0.2/A1
ReL = FeL/A1
Ft2.0 -- the tensile force from the sample is deformed to the total extension is 2% (N); Fp0.2 -- the tensile force when the non-proportional elongation of the sample is 2% after the heat treatment (when there is no obvious yield) (N);
FeL -- the tensile strength when the sample, after the heat treatment, shows lower yielding (N);
A0 -- the original cross-sectional area of the sample (mm2);
A1 -- the sample cross-sectional area after 2% pre-strain (mm2).
A.3 Heat treatment conditions