Q/BQB 620-2018 English PDF (QBQB620-2018)

Delivery: 3 seconds. Download true-PDF + Invoice.
Get QUOTATION in 1-minute: Click Q/BQB 620-2018
Historical versions: Q/BQB 620-2018
Preview True-PDF (Reload/Scroll if blank)

Q/BQB 620-2018: Low crack susceptibility high strength steel plates for hydropower
Q/BQB 620-2018
ENTERPRISE STANDARD OF BAOSHAN
IRON and STEEL CO., LTD.
Replacing Q/BQB 620-2013
Low crack susceptibility high strength
steel plates for hydropower
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 ... 4 
2 Normative references ... 4 
3 General technical requirements ... 5 
4 Classification and code ... 5 
5 Information required for ordering ... 6 
6 Dimension, shape, weight, and tolerances ... 6 
7 Technical requirements ... 7 
8 Inspection and test ... 11 
Low crack susceptibility high strength
steel plates for hydropower
1 Scope
This Standard specifies the dimension, shape, technical requirements,
inspection and test, marking, and inspection documents, etc. of low crack
susceptibility high strength steel plates for hydropower.
This Standard applies to low welding crack susceptibility high strength steel
plates for hydropower produced by Baoshan Iron and Steel Co., Ltd.
2 Normative references
The following documents are indispensable for the application of this document.
For the dated references, only the editions with the dates indicated are
applicable to this document. For the undated references, the latest edition
(including all the amendments) are applicable to this document.
GB/T 223 Methods for Chemical Analysis of Iron, Steel and Alloy
GB/T 228.1-2010 Metallic materials - Tensile testing - Part 1: Method of test
at room temperature
GB/T 229 Metallic Materials - Charpy Pendulum Impact Test Method
GB/T 232 Metallic materials - Bend test
GB/T 709-2006 Dimension shape weight and tolerances for hot-rolled steel
plates and sheets
GB/T 2970 Method for ultrasonic testing of thicker steel plates
GB/T 2975-1998 Steel and steel products - Location and preparation of test
pieces for mechanical testing
GB/T 4160 Steel-strain ageing sensibility test (Charpy impact method)
GB/T 4336 Carbon and low-alloy steel - Determination of multi-element
contents - Spark discharge atomic emission spectrometric method (routine
method)
GB/T 5313 Steel plates with through-thickness characteristics
GB/T 20066 Steel and Iron - Sampling and Preparation of Samples for the
Determination of Chemical Composition
GB/T 20123 Steel and iron - Determination of total carbon and sulfur content
- Infrared absorption method after combustion in an induction furnace
(routine method)
GB/T 20125 Low-alloy steel - Determination of multi-element contents -
Inductively coupled plasma atomic emission spectrometric method
JB/T 4730.3-2005 Nondestructive testing of pressure equipment - Part 3:
Ultrasonic testing
NB/T 47013.3-2015 Nondestructive testing of pressure equipment - Part 3:
Ultrasonic testing
Q/BQB 600 General technical requirements for steel plates
3 General technical requirements
Unless otherwise specified in this Standard, steel plates supplied in accordance
with this Standard shall comply with the corresponding requirements of Q/BQB
600.
4 Classification and code
4.1 Designation representation method
The steel’s designation consists of the first “B” of the pinyin letters for “Bao” of
Baosteel, the value of specified minimum tensile strength (in MPa), the English
letters representing the characteristics, the use, the delivery state, and the
quality grade. When representing low welding crack susceptibility, USE the
initials “CF” of English “Crack Free”. For hydropower, USE the initial “H” of
English “Hydropower”. When the delivery state is quenched and tempered state,
USE “Q”; and when it is thermomechanical rolled, USE “M” to represent. When
the impact toughness is required in the quality grade, USE the letter “L” of “Low
temperature” to represent. USE “2”, “4”, and “5” to distinguish the impact test
temperatures of -20°C, -40°C, and -50°C respectively.
4.2 The designation, delivery state, nominal thickness, and use of the steel plate
are shown in Table 1.
supplier and the purchaser, and indicated in the contract, it may also be
delivered in mill-edge (untrimmed edge).
7.4 Mechanical and technological properties
7.4.1 The mechanical and technological properties of the steel plate shall
comply with the requirements of Table 6.
7.4.2 The impact absorbed energy is the average of the test results of a set of
three samples. It is allowed that the test result of one of the samples is less
than the specified value. But it shall not be less than 70% of the specified value.
7.4.3 The impact test is only applicable to steel plates with a thickness of 6mm
or more. When the impact test is performed on a steel plate having a thickness
of 12mm or more, the standard sample of 10.0mm×10.0mm×55mm shall be
used; and the test results shall meet the specified values in the table. When
the impact test is performed on a steel plate with a thickness of 6mm or more
and less than 12.0mm, the auxiliary sample of 7.5mm×10.0mm×55mm or
5.0mm×10.0mm×55mm shall be used; and the test results shall not be less
than 75% or 50% of the specified values in the table, respectively.
7.4.4 If the impact test result does not meet the specified requirements, on the
same sampled product, three other samples can be taken for inspection. At this
time, the test result (average) of the six samples before and after shall not be
less than the specified value; and there can be no more than two samples below
the specified value; only one of the values is allowed to be less than 70% of the
specified value.
7.5 Surface quality
7.5.1 Defects such as cracks, bubbles, scabbing, folding, and inclusions are not
allowed on the surface of the steel plate. If there are the above defects, cleaning
is allowed. The depth of cleaning is calculated from the actual dimension of the
steel plate; shall not exceed half the thickness tolerance of the steel plate. The
minimum thickness of the steel plate shall be guaranteed. The defect cleaning
area shall be smooth and free of edges and corners. Steel plates shall not be
layered.
7.5.2 It is allowed that there are other defects. However, their depths, calculated
from the actual dimension of the steel plate, shall not exceed half the allowable
tolerance of the thickness. It shall also ensure that the thickness of the defect
does not exceed the minimum allowable thickness of the steel plate.