Codeofchina.com is in charge of this English translation. In case of any doubt about the English translation, the Chinese original shall be considered authoritative.
This specification replaces GJB 1663-1993 Specification for 10CrNi3MoV, 10CrNi3MoCu and 10CrNi2MoCu steel plates for submarine.
The following main changes have been made in this specification with respect to GJB 1663-1993:
a) The name of the specification is modified to Specification for 10CrNi3MoV, 10CrNi3MoCu and 10CrNi2MoCu steel plates for military ship;
b) "The converter + secondary refining and continuous casting" is added to the smelting method;
c) The contents of C, S and P in chemical composition are adjusted, and the requirements for control indexes of [H], [O] and [N] in steel are added;
d) The requirement that “steel plates may be delivered in hot rolled state” is deleted, while the requirement that “steel plates should be delivered after subjected to shot peening and surface coating treatment” is added;
e) As for 921A, the mechanical properties are graded according to the nominal thickness, and the requirements of tensile strength and impact property at -84℃ are added; as for 923A, the requirement for impact property at -20℃ is added;
f) The requirements for fracture surface test results and fracture surface specimen dimensions are modified;
g) The requirements for dimension, tolerance and weight are modified;
h) "Macrostructure" and "Z-direction tensile" are added in the first article inspection;
i) The sampling position and method in the quality conformance inspection are modified;
j) Macrostructure inspection, Z-direction tensile inspection, product marking inspection and rounding of mechanical and chemical test results are added as inspection methods.
Annexes A and B to this specification are normative.
This specification is under the jurisdiction of China Metallurgical Information and Standardization Institute.
GJB 1663 was issued for the first time in 1993.
Specification for 10CrNi3MoV, 10CrNi3MoCu and 10CrNi2MoCu steel plates for military ship
1 Scope
This specification specifies detailed requirements of 10CrNi3MoV (coded as 921A), 10CrNi3MoCu (coded as 922A) and 10CrNi2MoCu (coded as 923A) steel plates.
This specification is applicable to steel plates with thicknesses of 5mm~9mm (923A), 10mm~35mm (921A) and 36mm~70mm (922A) for military ships.
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 223.3 Methods for chemical analysis of iron, steel and alloy - The diantipyrylmethane phosphomolybdate gravimetric method for the determination of phosphorus content
GB/T 223.5 Steel and iron - Determination of acid-soluble silicon and total silicon content - Reduced molybdosilicate spectrophotometric method
GB/T 223.11 Iron, steel and alloy - Determination of chromium content - Visual titration or potentiometric titration method
GB/T 223.14 Methods for chemical analysis of iron, steel and alloy - The N-benzoy-N-phenylhydroxylamine extraction photometric method for the determination of vanadium content
GB/T 223.18 Methods for chemical analysis of iron, steel and alloy - The sodium thiosulfate separation iodimetric method for the determination of copper content
GB/T 223.19 Methods for chemical analysis of iron steel and alloy - The neocuproine-chloroform extraction photometric method for the determination of copper content
GB/T 223.25 Methods for chemical analysis of iron, steel and alloy - The dimethylglyoxime gravimetric method for the determination of nickel content
GB/T 223.26 Iron steel and alloy - Determination of molybdenum content - The thiocyanate spectrophotometric method
GB/T 223.37 Methods for chemical analysis of iron, steel and alloy - The indophenol blue photometric methods for the determination of nitrogen content after distillation separation
GB/T 223.58 Methods for chemical analysis of iron, steel and alloy - The sodium arsenite-sodium nitrite titrimetric method for the determination of manganese content
GB/T 223.59 Iron, steel and alloy - Determination of phosphorus content - Bismuth phosphomolybdate blue spectrophotometric method and antimony phosphomolybdate blue spectrophotometric method
GB/T 223.60 Methods for chemical analysis of iron,steel and alloy - The perchloric acid dehydration gravimetric method for the determination of silicon content
GB/T 223.61 Methods for chemical analysis of iron, steel and alloy - The ammonium phosphomolybdate volumetric method for the determination of phosphorus content
GB/T 223.62 Methods for chemical analysis of iron, steel and alloy - The butyl acetate extraction photometric method for the determination of phosphorus content
GB/T 223.63 Methods for chemical analysis of iron, steel and alloy - The sodium (potassium) periodate photometric method for the determination of manganese content
GB/T 223.64 Iron, steel and alloy - Determination of manganese content - Flame atomic absorption spectrometric method
GB/T 223.67 Iron, steel and alloy - Determination of sulfur content - Methylene blue spectrophotometric method
GB/T 223.68 Methods for chemical analysis of iron, steel and alloy - The potassium iodate titration method after combustion in the pipe furnace for the determination of sulfur content
GB/T 223.69 Iron, steel and alloy - Determination of carbon contents - Gas-volumetric method after combustion in the pipe furnace
GB/T 223.71 Methods for chemical analysis of iron, steel and alloy - The gravimetric method after combustion in the pipe furnace for the determination of carbon content
GB/T 223.72 Iron, steel and alloy - Determination of sulfur content - Gravimetric method
GB/T 223.76 Methods for chemical analysis of iron, steel and alloy - The flame atomic absorption spectrometric method for the determination of vanadium content
GB/T 223.82 Steel and iron - Determination of hydrogen content - Thermal conductivity/infrared method after fusion under inert gas
GB/T 223.85 Steel and iron - Determination of sulfur content - Infrared absorption method after combustion in an induction furnace
GB/T 226 Test method for macrostructure and defect of steel by etching
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 247 General rule of package, mark and certification for steel plates (sheets) and strips
GB/T 709 Dimension, shape, weight and tolerances for hot-rolled steel plates and sheets
GB/T 1979 Standard diagrams for macrostructure and defect of structural steels
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 5482 Test method of metallic materials - Dynamic tear
GB/T 8170 Rules of rounding off for numerical values & expression and judgment of limiting values
GB/T 11259 Non-destructive testing - Practice for fabrication and control of steel reference blocks used in ultrasonic testing
GB/T 11261 Steel and iron - Determination of oxygen content - The pulse heating inert gas fusion-infra-red absorption method
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 (routine method)
GB/T 20125 Low-alloy steel - Determination of multi-element contents - Inductively coupled plasma atomic emission spectrometric method
GJB 593.1 Specification for controlling the quality of nondestructive testing - Ultrasonic testing (longitudinal and transverse wave)
GJB 607A-1998 Methods for explosion test of metallic materials and weldments
JB/T 10061 Commonly used specification for A-mode ultrasonic flaw detector using pulse echo technique
JB/T 10062 Testing methods for performance of probes used in ultrasonic flaw detection
CCS Rules for materials and welding
3 Requirements
3.1 Smelting process
Steel shall be smelted with the electric arc furnace (EAF) + secondary refining and die casting or the converter + secondary refining and continuous casting.
3.2 Chemical composition
3.2.1 The chemical composition of the steel (melting analysis) shall meet those specified in Table 1.
Table 1 Chemical composition
Designation Code Chemical composition (mass fraction), %
C Si Mn S P Ni Cr Mo V Cu
≤
10CrNi3MoV 921A 0.06~
0.11 0.17~
0.37 0.30~
0.60 0.010 0.015 2.60~
3.00 0.90~
1.20 0.20~
0.27 0.04~
0.10 —
10CrNi3MoCu 922A 0.06~
0.11 0.17~
0.37 0.30~
0.60 0.010 0.015 2.20~
2.50 1.20~
1.60 0.20~
0.27 — 0.80~
1.10
10CrNi2MoCu 923A 0.06~
0.11 0.17~
0.37 0.30~
0.60 0.010 0.015 2.00~
2.30 0.70~
1.00 0.17~
0.25 — 0.80~
1.10
3.2.2 Upon request of the demander and indicated in the contract, in steel plates, the content of [H] shall be ≤ 0.0002%, that of [O] ≤ 0.004%, and that of [N] in continuous casting billet and die casting billet shall be ≤ 0.006% and ≤ 0.008% respectively.
3.2.3 The chemical composition tolerance of steel plates shall meet those specified in Table 2.
Table 2 Tolerance of chemical composition of finished products
Element C Si Mn Ni Cr Mo V Cu
Tolerance of ingredients (mass fraction), % ±0.01 ±0.03 ±0.03 ±0.05 ±0.05 ±0.02 ±0.01 ±0.03
3.3 Delivery state
3.3.1 Steel plates shall be delivered in as-quenched and high-temperature tempered condition.
3.3.2 Steel plates shall be trimmed before being delivered. If indicated in the contract or purchase order, they may be delivered without cutting longitudinal edges.
3.3.3 Steel plates should be delivered after subjected to shot peening and surface coating treatment, with specific requirements determined jointly by the manufacturer and the orderer through negotiation.
3.4 Mechanical properties
3.4.1 The mechanical properties of steel plates after quenching and high temperature tempering heat treatment shall meet those specified in Table 3.
Table 3 Mechanical properties
Designation Code Nominal thickness
mm Tensile property Impact property
Lower yield strengtha
ReL
MPa Tensile strength
Rm
MPa Percentage elongation after fracture
A
% Percentage reduction of area
Z
% Test temperature
℃ Impact absorbed energyb
KV2
J Percent shear fracture appearancec
FA
%
≥ ≥
10CrNi3MoV 921A 11~35 590~730 ≥655 16 50 -84d 47 50
-20 80 100
10 -84d 31 50
-20 53 100
10CrNi3MoCu 922A 36~70 510~650 As recorded 16 50 -20 80 100
10CrNi2MoCu 923A 5~9 510~670 16 — -20 53
The impact property of 5mm 923A steel plates shall be inspected based on actual plate thickness, and inspection results shall be recorded.
a If yielding is not obvious, the specified plastic elongation strength, Rp0.2, or the specified residual elongation strength, Rr0.2, shall be determined.
b It represents the arithmetic mean of three impact absorbed energy obtained using a group of three specimens, of which, only one specimen is allowed to be lower than the specified value, by 7J at most.
c It represents the arithmetic mean of three percent shear fracture appearance obtained using a group of three specimens.
d It is only applicable to continuous casting 921A steel plates.
3.4.2 In the temperature shock tests of longitudinal and transverse series, it is necessary to record the inspection results, and plot the complete transition curves of impact absorbed energy and percent shear fracture appearance to temperature.
3.4.3 Continuous casting steel plates shall be subjected to Z-direction tensile test, for which, the average percentage reduction of area and the minimum percentage reduction of area of a single specimen shall be recorded.
3.5 Processing property
A 923A steel plate shall be subjected to a bending test. The specimen shall have a width seven times and a bending radius twice the nominal thickness of the steel plate respectively. If the specimen is bent to 120°, it shall be free of any visible crack on the outer surface bent.
3.6 Macrostructure
Continuous casting steel plates shall be subjected to macrostructure inspection, with the inspection results recorded.
3.7 Dynamic tear test and explosion test
921A, 922A and 923A steel plates shall be subjected to both dynamic tear test and explosion test, whose results shall meet those specified in Annex A.
3.8 Fracture surface
921A and 922A steel plates shall be subjected to fracture surface inspection, whose results shall meet the following requirements:
a) The fracture surface shall be fibrous, and may have grains;
b) The fracture surface shall be free of any flakes or bright lines;
c) As for 921A steel plates, the fracture surface shall be free of any penetrating cracking streamline or shall have at most two cracking streamlines caused by tearing longer than 50% of the fracture surface length;
d) As for 922A steel plates, the area of cracking or non-cracking streamline on the fracture surface shall not exceed 75% the cross-sectional area of the fracture surface.
Note: The cracking streamline is the cracking line on the fracture surface parallel to the surface of the steel plate.
3.9 Ultrasonic testing
921A, 922A and 923A steel plates (other than rolled plates) shall be subjected to ultrasonic testing. For the inner area of steel plates, the testing results shall meet those specified in Table 4; for the periphery of steel plate or the area within the predetermined groove lines, the testing results shall meet those specified in Table 5.
Foreword i
1 Scope
2 Normative references
3 Requirements
4 Requirements for quality assurance
5 Delivery preparation
6 Instructions
Annex A (Normative) Dynamic tear test and explosion test
Annex B (Normative) Ultrasonic testing method
Codeofchina.com is in charge of this English translation. In case of any doubt about the English translation, the Chinese original shall be considered authoritative.
This specification replaces GJB 1663-1993 Specification for 10CrNi3MoV, 10CrNi3MoCu and 10CrNi2MoCu steel plates for submarine.
The following main changes have been made in this specification with respect to GJB 1663-1993:
a) The name of the specification is modified to Specification for 10CrNi3MoV, 10CrNi3MoCu and 10CrNi2MoCu steel plates for military ship;
b) "The converter + secondary refining and continuous casting" is added to the smelting method;
c) The contents of C, S and P in chemical composition are adjusted, and the requirements for control indexes of [H], [O] and [N] in steel are added;
d) The requirement that “steel plates may be delivered in hot rolled state” is deleted, while the requirement that “steel plates should be delivered after subjected to shot peening and surface coating treatment” is added;
e) As for 921A, the mechanical properties are graded according to the nominal thickness, and the requirements of tensile strength and impact property at -84℃ are added; as for 923A, the requirement for impact property at -20℃ is added;
f) The requirements for fracture surface test results and fracture surface specimen dimensions are modified;
g) The requirements for dimension, tolerance and weight are modified;
h) "Macrostructure" and "Z-direction tensile" are added in the first article inspection;
i) The sampling position and method in the quality conformance inspection are modified;
j) Macrostructure inspection, Z-direction tensile inspection, product marking inspection and rounding of mechanical and chemical test results are added as inspection methods.
Annexes A and B to this specification are normative.
This specification is under the jurisdiction of China Metallurgical Information and Standardization Institute.
GJB 1663 was issued for the first time in 1993.
Specification for 10CrNi3MoV, 10CrNi3MoCu and 10CrNi2MoCu steel plates for military ship
1 Scope
This specification specifies detailed requirements of 10CrNi3MoV (coded as 921A), 10CrNi3MoCu (coded as 922A) and 10CrNi2MoCu (coded as 923A) steel plates.
This specification is applicable to steel plates with thicknesses of 5mm~9mm (923A), 10mm~35mm (921A) and 36mm~70mm (922A) for military ships.
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 223.3 Methods for chemical analysis of iron, steel and alloy - The diantipyrylmethane phosphomolybdate gravimetric method for the determination of phosphorus content
GB/T 223.5 Steel and iron - Determination of acid-soluble silicon and total silicon content - Reduced molybdosilicate spectrophotometric method
GB/T 223.11 Iron, steel and alloy - Determination of chromium content - Visual titration or potentiometric titration method
GB/T 223.14 Methods for chemical analysis of iron, steel and alloy - The N-benzoy-N-phenylhydroxylamine extraction photometric method for the determination of vanadium content
GB/T 223.18 Methods for chemical analysis of iron, steel and alloy - The sodium thiosulfate separation iodimetric method for the determination of copper content
GB/T 223.19 Methods for chemical analysis of iron steel and alloy - The neocuproine-chloroform extraction photometric method for the determination of copper content
GB/T 223.25 Methods for chemical analysis of iron, steel and alloy - The dimethylglyoxime gravimetric method for the determination of nickel content
GB/T 223.26 Iron steel and alloy - Determination of molybdenum content - The thiocyanate spectrophotometric method
GB/T 223.37 Methods for chemical analysis of iron, steel and alloy - The indophenol blue photometric methods for the determination of nitrogen content after distillation separation
GB/T 223.58 Methods for chemical analysis of iron, steel and alloy - The sodium arsenite-sodium nitrite titrimetric method for the determination of manganese content
GB/T 223.59 Iron, steel and alloy - Determination of phosphorus content - Bismuth phosphomolybdate blue spectrophotometric method and antimony phosphomolybdate blue spectrophotometric method
GB/T 223.60 Methods for chemical analysis of iron,steel and alloy - The perchloric acid dehydration gravimetric method for the determination of silicon content
GB/T 223.61 Methods for chemical analysis of iron, steel and alloy - The ammonium phosphomolybdate volumetric method for the determination of phosphorus content
GB/T 223.62 Methods for chemical analysis of iron, steel and alloy - The butyl acetate extraction photometric method for the determination of phosphorus content
GB/T 223.63 Methods for chemical analysis of iron, steel and alloy - The sodium (potassium) periodate photometric method for the determination of manganese content
GB/T 223.64 Iron, steel and alloy - Determination of manganese content - Flame atomic absorption spectrometric method
GB/T 223.67 Iron, steel and alloy - Determination of sulfur content - Methylene blue spectrophotometric method
GB/T 223.68 Methods for chemical analysis of iron, steel and alloy - The potassium iodate titration method after combustion in the pipe furnace for the determination of sulfur content
GB/T 223.69 Iron, steel and alloy - Determination of carbon contents - Gas-volumetric method after combustion in the pipe furnace
GB/T 223.71 Methods for chemical analysis of iron, steel and alloy - The gravimetric method after combustion in the pipe furnace for the determination of carbon content
GB/T 223.72 Iron, steel and alloy - Determination of sulfur content - Gravimetric method
GB/T 223.76 Methods for chemical analysis of iron, steel and alloy - The flame atomic absorption spectrometric method for the determination of vanadium content
GB/T 223.82 Steel and iron - Determination of hydrogen content - Thermal conductivity/infrared method after fusion under inert gas
GB/T 223.85 Steel and iron - Determination of sulfur content - Infrared absorption method after combustion in an induction furnace
GB/T 226 Test method for macrostructure and defect of steel by etching
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 247 General rule of package, mark and certification for steel plates (sheets) and strips
GB/T 709 Dimension, shape, weight and tolerances for hot-rolled steel plates and sheets
GB/T 1979 Standard diagrams for macrostructure and defect of structural steels
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 5482 Test method of metallic materials - Dynamic tear
GB/T 8170 Rules of rounding off for numerical values & expression and judgment of limiting values
GB/T 11259 Non-destructive testing - Practice for fabrication and control of steel reference blocks used in ultrasonic testing
GB/T 11261 Steel and iron - Determination of oxygen content - The pulse heating inert gas fusion-infra-red absorption method
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 (routine method)
GB/T 20125 Low-alloy steel - Determination of multi-element contents - Inductively coupled plasma atomic emission spectrometric method
GJB 593.1 Specification for controlling the quality of nondestructive testing - Ultrasonic testing (longitudinal and transverse wave)
GJB 607A-1998 Methods for explosion test of metallic materials and weldments
JB/T 10061 Commonly used specification for A-mode ultrasonic flaw detector using pulse echo technique
JB/T 10062 Testing methods for performance of probes used in ultrasonic flaw detection
CCS Rules for materials and welding
3 Requirements
3.1 Smelting process
Steel shall be smelted with the electric arc furnace (EAF) + secondary refining and die casting or the converter + secondary refining and continuous casting.
3.2 Chemical composition
3.2.1 The chemical composition of the steel (melting analysis) shall meet those specified in Table 1.
Table 1 Chemical composition
Designation Code Chemical composition (mass fraction), %
C Si Mn S P Ni Cr Mo V Cu
≤
10CrNi3MoV 921A 0.06~
0.11 0.17~
0.37 0.30~
0.60 0.010 0.015 2.60~
3.00 0.90~
1.20 0.20~
0.27 0.04~
0.10 —
10CrNi3MoCu 922A 0.06~
0.11 0.17~
0.37 0.30~
0.60 0.010 0.015 2.20~
2.50 1.20~
1.60 0.20~
0.27 — 0.80~
1.10
10CrNi2MoCu 923A 0.06~
0.11 0.17~
0.37 0.30~
0.60 0.010 0.015 2.00~
2.30 0.70~
1.00 0.17~
0.25 — 0.80~
1.10
3.2.2 Upon request of the demander and indicated in the contract, in steel plates, the content of [H] shall be ≤ 0.0002%, that of [O] ≤ 0.004%, and that of [N] in continuous casting billet and die casting billet shall be ≤ 0.006% and ≤ 0.008% respectively.
3.2.3 The chemical composition tolerance of steel plates shall meet those specified in Table 2.
Table 2 Tolerance of chemical composition of finished products
Element C Si Mn Ni Cr Mo V Cu
Tolerance of ingredients (mass fraction), % ±0.01 ±0.03 ±0.03 ±0.05 ±0.05 ±0.02 ±0.01 ±0.03
3.3 Delivery state
3.3.1 Steel plates shall be delivered in as-quenched and high-temperature tempered condition.
3.3.2 Steel plates shall be trimmed before being delivered. If indicated in the contract or purchase order, they may be delivered without cutting longitudinal edges.
3.3.3 Steel plates should be delivered after subjected to shot peening and surface coating treatment, with specific requirements determined jointly by the manufacturer and the orderer through negotiation.
3.4 Mechanical properties
3.4.1 The mechanical properties of steel plates after quenching and high temperature tempering heat treatment shall meet those specified in Table 3.
Table 3 Mechanical properties
Designation Code Nominal thickness
mm Tensile property Impact property
Lower yield strengtha
ReL
MPa Tensile strength
Rm
MPa Percentage elongation after fracture
A
% Percentage reduction of area
Z
% Test temperature
℃ Impact absorbed energyb
KV2
J Percent shear fracture appearancec
FA
%
≥ ≥
10CrNi3MoV 921A 11~35 590~730 ≥655 16 50 -84d 47 50
-20 80 100
10 -84d 31 50
-20 53 100
10CrNi3MoCu 922A 36~70 510~650 As recorded 16 50 -20 80 100
10CrNi2MoCu 923A 5~9 510~670 16 — -20 53
The impact property of 5mm 923A steel plates shall be inspected based on actual plate thickness, and inspection results shall be recorded.
a If yielding is not obvious, the specified plastic elongation strength, Rp0.2, or the specified residual elongation strength, Rr0.2, shall be determined.
b It represents the arithmetic mean of three impact absorbed energy obtained using a group of three specimens, of which, only one specimen is allowed to be lower than the specified value, by 7J at most.
c It represents the arithmetic mean of three percent shear fracture appearance obtained using a group of three specimens.
d It is only applicable to continuous casting 921A steel plates.
3.4.2 In the temperature shock tests of longitudinal and transverse series, it is necessary to record the inspection results, and plot the complete transition curves of impact absorbed energy and percent shear fracture appearance to temperature.
3.4.3 Continuous casting steel plates shall be subjected to Z-direction tensile test, for which, the average percentage reduction of area and the minimum percentage reduction of area of a single specimen shall be recorded.
3.5 Processing property
A 923A steel plate shall be subjected to a bending test. The specimen shall have a width seven times and a bending radius twice the nominal thickness of the steel plate respectively. If the specimen is bent to 120°, it shall be free of any visible crack on the outer surface bent.
3.6 Macrostructure
Continuous casting steel plates shall be subjected to macrostructure inspection, with the inspection results recorded.
3.7 Dynamic tear test and explosion test
921A, 922A and 923A steel plates shall be subjected to both dynamic tear test and explosion test, whose results shall meet those specified in Annex A.
3.8 Fracture surface
921A and 922A steel plates shall be subjected to fracture surface inspection, whose results shall meet the following requirements:
a) The fracture surface shall be fibrous, and may have grains;
b) The fracture surface shall be free of any flakes or bright lines;
c) As for 921A steel plates, the fracture surface shall be free of any penetrating cracking streamline or shall have at most two cracking streamlines caused by tearing longer than 50% of the fracture surface length;
d) As for 922A steel plates, the area of cracking or non-cracking streamline on the fracture surface shall not exceed 75% the cross-sectional area of the fracture surface.
Note: The cracking streamline is the cracking line on the fracture surface parallel to the surface of the steel plate.
3.9 Ultrasonic testing
921A, 922A and 923A steel plates (other than rolled plates) shall be subjected to ultrasonic testing. For the inner area of steel plates, the testing results shall meet those specified in Table 4; for the periphery of steel plate or the area within the predetermined groove lines, the testing results shall meet those specified in Table 5.
Contents of GJB 1663A-2018
Foreword i
1 Scope
2 Normative references
3 Requirements
4 Requirements for quality assurance
5 Delivery preparation
6 Instructions
Annex A (Normative) Dynamic tear test and explosion test
Annex B (Normative) Ultrasonic testing method
