Foreword
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This specification revises GJB 1496A-2000 Specification for 28Cr2Mo, 26SiMnMo and 22SiMn2TiB steel plates for armour use. The following main changes have been made in this specification with respect to GJB 1496A-2000:
a) The accuracy requirements of permissible deviations for various specifications of steel plates for armour use are improved;
b) On the premise of retaining the bullet-proof performance requirements of the original 37 mm armour-piercing shell, the bullet-proof performance requirements of the steel plate for armour use for the 25 mm armour-piercing shell are added;
c) The contents of the "first article inspection" are added, and the requirements and methods of inspection and acceptance of steel plates for armour use are supplemented, modified and refined.
Annexes A and B to this specification are normative.
This specification was proposed by the Army Equipment Research and Procurement Department of the General Armaments Department of the PLA.
The previous editions of this specification are GJB 1496-1992 and GJB 1496A-2000.
Specification for 28Cr2Mo, 26SiMnMo and 22SiMn2TiB steel plates
1 Scope
This specification specifies the detailed requirements for rolled homogeneous armour steel plates of 28Cr2Mo (code GY4), 26SiMnMo (code GY5), and 22SiMn2TiB (code 616) used for armoured vehicles.
This specification is applicable to GY4 steel plates with a thickness of 10 mm, 12 mm, 15 mm, 20 mm, 25 mm or 30 mm, GY5 steel plates with a thickness of 5 mm, 6 mm, 8 mm, 10 mm, 12 mm, 15 mm or 20 mm and 616 steel plates with a thickness of 5 mm, 6 mm, 8 mm, 10 mm, 12 mm, 15 mm, 16 mm, 18 mm, 20 mm or 22 mm for armoured vehicles.
2 Normative references
The following normative documents contain provisions which, through reference in this text, constitute provisions of this specification. For dated reference, subsequent amendments (excluding corrections), or revisions, of any of these publications do not apply to this specification. However, parties to agreements based on this specification are encouraged to investigate the possibility of applying the most recent editions of the normative documents indicated below. For undated references or references with version not indicated, the latest edition of the normative document referred to applies.
GB/T 222 Method of sampling steel for determination of chemical composition and permissible variations for product analysis
GB/T 229 Metallic materials - Charpy notch impact test
GB/T 231.1 Metallic materials - Brinell hardness test
GB/T 247 General rule of acceptance, package, mark and certification for steel plates (sheets) and strips
GB/T 709 Dimension, shape, weight and tolerance for hot-rolled steel strip, plate and sheet
GJB 59.17 Test operations procedure for armoured vehicles - Armour plate shell-proof test
GJB 59.18 Test operations procedure for armoured vehicles
- Armour plate bullet-proof test
ZBY 230 Commonly used specification A-mode ultrasonic flaw detector using pulse echo technique
3 Requirements
3.1 Chemical composition
3.1.1 The designation and chemical composition (smelting analysis) of steel shall meet those specified in Table 1 and the content of acid-soluble boron shall be within 0.0003% to 0.0005%.
Table 1 Chemical composition of the steel plate
3.1.2 The permissible deviations of chemical compositions in the steel plate shall meet those specified in GB/T 222.
3.2 Mechanical properties
3.2.1 Hardness
The Brinell hardness of steel plates and quenched and tempered fracture specimens in high-temperature tempered or hot-rolled conditions shall meet those specified in Table 2.
Table 2 Brinell hardness of steel plates and quenched and tempered fracture specimens
3.2.2 Impact absorption energy
After heat treatment, the GY4 steel plate with a thickness of not less than 25 mm and the 616 steel plate with a thickness greater than 10 mm shall be tested for transverse Charpy V-notch impact absorption energy at -40°C.
Foreword i
1 Scope
2 Normative references
3 Requirements
4 Quality assurance requirements
5 Delivery preparation
6 Instructions
Annex A (Normative) National standards for commonly used chemical analysis methods
Annex B (Normative) Method for determination of bullet speed for shooting test
