Q/BQB 517-2023 Wire rods for cold heading
1 Scope
This document specifies the dimension, shape, mass and permissible tolerance, technical requirements, inspection and test, packaging, marking and inspection document of wire rods for cold heading.
This document is applicable to the hot-rolled wire rods for cold heading manufactured by Baoshan Iron and Steel Co., Ltd. It is mainly used for manufacturing high-grade cold-formed fasteners and irregular parts used in automobile, electronics, machinery and other industries.
2 Normative references
The following referenced documents are indispensable for the application of this document. For dated references, only the edition cited applies. For undated references, the latest edition of the referenced document (including any amendments) applies.
GB/T 222 Permissible tolerances for chemical composition of steel products
GB/T 223 Methods for chemical analysis of iron, steel and alloy
GB/T 224-2019 Determination of depth of decarburization of steel
GB/T 228.1-2021 Metallic materials - Tensile testing - Part 1: Method of test at room temperature
GB/T 230.1 Metallic materials - Rockwell hardness test - Part 1: Test method
GB/T 2975 Steel and steel products - Location and preparation of samples and test pieces for mechanical testing
GB/T 4336 Carbon and low-alloy steel - Determination of multi-element contents - Spark discharge atomic emission spectrometric method (routine method)
GB/T 6394 Determination of estimating the average grain size of metal
GB/T 8170 Rules of rounding off for numerical values & expression and judgement of limiting values
GB/T 10561-2005 Steel - Determination of content of nonmetallic inclusions - Micrographic method using standards diagrams
GB/T 11261 Steel and iron - Determination of oxygen content - The pulse heating inert gas fusion-infra-red absorption method
GB/T 13298 Inspection methods of microstructure for metals
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 20124 Steel and iron - Determination of nitrogen content - Thermal conductimetric method after fusion in a current of inert gas
GB/T 20125 Low-alloy steel - Determination of multi-element contents - Inductively coupled plasma atomic emission spectrometric method
GB/T 20126 Unalloyed steel - Determination of low carbon content - Part 2: Infrared absorption method after combustion in an induction furnace (with preheating)
YB/T 5293 Metallic materials - Forging test
Q/BQB 500 General requirements of packaging, marking and inspection document for wire rods
Q/BQB 501 Dimension, shape, mass and tolerance for wire rod
3 Terms and definitions
There are no terms and definitions that need to be defined in this document.
4 Ordering contents
The contract or order for ordering wire rods according to this document shall cover the followings:
a) No. of this company standard;
b) Designation (See Tables 1 and 2);
c) Specification and dimension precision grade;
d) Weight and coil weight group (i.e., I, II or III, see Q/BQB 501. If not specified, the requirements of Group I coil weight shall prevail.) ;
e) Packaging method;
f) Special quality requirements for chemical composition (order code Z1, see Annex A), if required;
g) Special quality requirements for surface quality (order code Z4, see Annex A), if required;
h) Other special requirements.
5 Dimension, shape, mass and permissible tolerance
5.1 In case of Group I coil weight, the weight shall generally be 1,700kg to 2,400kg; each delivery batch is allowed to have 10% of coils (coils less than two are regard as two coils) less than 1,700kg but not less than 1,000kg.
5.2 Other requirements for Dimension, shape, mass and permissible tolerance shall be in accordance with Q/BQB 501.
6 Technical requirements
6.1 Designation and chemical composition
6.1.1 The designation and chemical composition (melting composition) of steels for cold heading shall meet those specified in Table 1. Designation and chemical composition (melting composition) of Series B steels for cold heading shall meet those specified in Table 2.
6.1.2 The permissible tolerances for chemical composition of finished wire rods shall be in accordance with GB/T 222.
6.1.3 As required by the purchaser, wire rods of other designations or with other chemical compositions may be supplied upon the agreement between the supplier and purchaser.
Foreword i
1 Scope
2 Normative references
3 Terms and definitions
4 Ordering contents
5 Dimension, shape, mass and permissible tolerance
6 Technical requirements
7 Inspection and test
8 Packaging, marking and inspection documents
9 Rules of rounding off for numerical values
10 Annex
Annex A (Normative) Special quality requirements
Annex B (Informative) Comparison between similar designations in this document and relevant standards
