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 standard is drafted in accordance with the rules given in GB/T 1.1-2009.
This standard replaces GB/T 12754-2006 Prepainted steel sheet.
In addition to editorial changes, the following main technical changes have been made with respect to GB/T 12754-2006:
—— normative references of GB/T 228, GB/T 1839 and GB/T 2975 are deleted, and normative reference of GB/T 8170 is added (see clause 2 of this standard and clause 2 of Edition 2006);
—— the definition of “prepainted steel sheet” is modified (see 3.1 of this standard and 3.1 of Edition 2006);
—— the designation expression method is modified, with example added (see 4.1 of this standard and 4.1 of Edition 2006);
—— designation and purpose of prepainted steel sheet are deleted (see 4.2 of Edition 2006)
—— two types of steel substrate for prepainted steel sheet are added: hot-dip aluminium-silicon alloy steel substrate and hot-dip aluminum-magnesium alloy steel substrate (see Table 1);
—— the coating sheet in the previous edition is modified into ordinary coating sheet, and coating surface states are added: checkered sheet, velvet sheet, pearlescent sheet, and frosted sheet (see Table 1 of this standard and Table 2 of Edition 2006);
—— finish paint functions of ordinary, self-cleaning, anti-static, anti-bacterial, and thermal insulation are added (see Table 1);
—— the default dimension and flatness precision grade when ordering are added (see 5.2);
—— requirements are modified for the width, length, shape of prepainted steel sheet and the thickness of its steel substrate (see 6.2 of this standard and 6.1.3 of Edition 2006);
—— regulations are added for the cases when users have requirements on the inner diameter tolerance of steel coil (see Table 2);
—— requirements are added that the mechanical property, plating property and plating weight of the prepainted steel sheet shall meet the requirements of the standards for steel substrate of corresponding designation (see 7.1.1.1);
—— the recommended nominal plating weight of each steel substrate type under different corrosive environments is deleted (Table 4 of Edition 2006);
—— the requirement is added for the color difference of coating (see 7.1.2.3);
—— the grading and test time of resistance to neutral salt spray are modified (see 7.1.2.7 of this standard and 7.3.1 of Edition 2006);
—— the grading of accelerated weathering by ultraviolet lamp is modified, and the evaluations for discoloration and dulling are added (see 7.1.2.7 of this standard and 7.3.2 of Edition 2006);
—— requirements are modified for the test of accelerated weathering by ultraviolet lamp (see 7.1.2.8 of this standard and 7.3.2 of Edition 2006);
—— the antistatic property of antistatic prepainted steel sheet and self-cleaning property of the self-cleaning prepainted steel sheet are added (see 7.1.2.9 and 7.1.2.10);
—— descriptions and technical requirements are added for checkered sheet, velvet sheet, pearlescent sheet and frosted sheet (see 7.2.3, 7.2.4, 7.2.5 and 7.2.6);
—— the sampling number for test items other than coating thickness test is modified (see Table 8 of this standard and Table 11 of Edition 2006);
—— typical atmospheric environment types corresponding to different corrosivity classes in Annex A are modified, and permissible deviations of the dimension and shape of prepainted steel sheet are deleted (see Annex A of this standard and Annex A of Edition 2006);
—— Annex B Mechanical properties of the prepainted steel sheet is deleted (see Annex B of Edition 2006);
—— Annex C Table of comparison of designations of domestic and foreign steel substrates commonly used for prepainted steel sheet is deleted (see Annex C of Edition 2006);
——Annex D Typical atmospheric environment types corresponding to different corrosivity classes is modified (see Annex A of this standard and Annex D of Edition 2006).
This standard was proposed by the China Iron and Steel Association.
This standard is under the jurisdiction of SAC/TC 183 National Technical Committee on Iron and Steel of Standardization Administration of China.
The previous editions of this standard are as follows:
—— GB/T 12754-1991 and GB/T 12754-2006.
Prepainted steel sheet and strip
1 Scope
This standard specifies the terms and definitions, designation expression methods, classification and code, order details, dimension, shape, weight, technical requirements, test methods, inspection rules, packaging, marking, and product quality certificate in connection with prepainted steel sheet and strip.
This standard is applicable to the prepainted steel sheet and strip (hereinafter referred to as "prepainted steel sheet") for building exterior and interior applications. This standard may serve as a reference for prepainted steel sheet for household electrical appliances and other purposes.
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 247 General rule of package, mark and certification for steel plates (sheets) and strips
GB/T 1766-2008 Paints and varnishes - Rating schemes of degradation of coats
GB/T 8170 Rules of rounding off for numerical values & expression and judgement of limiting values
GB/T 13448 Test methods for prepainted steel sheet
GB/T 17505 Steel and steel products - General technical delivery requirements
3 Terms and definitions
For the purposes of this document, the following terms and definitions apply.
3.1
prepainted steel sheet
the product obtained by baking and curing after continuously coating organic coating materials on the steel substrate which has been subjected to surface pretreatment
3.2
steel substrate
steel strip for coating
3.3
top side
one of the two sides of the prepainted steel sheet that has higher requirements on color, coating property, surface quality, etc.
3.4
bottom side
the other side of the prepainted steel sheet opposite to the top side
3.5
building exterior applications
applications affected by exterior atmospheric environment
3.6
building interior applications
applications affected by interior atmosphere
3.7
coating hardness
the ability of the coating to resist mechanical actions such as scratch, friction, collision and indentation
3.8
flexibility
the ability of the coating to deform with the steel substrate without damage
3.9
adhesion
the degree of firmness between coatings or between coating and steel substrate
3.10
life to the first major maintenance
the interval time between the end of manufacturing and the time when the property of the original coating degrades to the condition that its protection on the steel substrate can only be maintained through overhaul
Note: Overhaul refers to the maintenance and repair work that must be carried out on the building when the paint film becomes incomplete due to weathering or the steel substrate is perforated, including repainting, local replacement, etc.
3.11
durability
the ability of the coating to reach the specified life to the first major maintenance
3.12
weathering
the phenomenon that the coating property gradually degrades under the influence of the application environment
4 Expression method, classification and code of designation
4.1 Designation expression methods
The designation of prepainted steel sheet consists of capital letter T plus the designation of steel substrate.
Example 1: TDX51D+Z
—— representing the prepainted steel sheet with a steel substrate of designation DX51D+Z.
Example 2: TDC01+ZE
—— representing the prepainted steel sheet with a steel substrate of designation DC01+ZE.
Example 3: TS300GD+AZ
—— representing the prepainted steel sheet with a steel substrate of designation S300GD+AZ.
4.2 Classification and code
4.2.1 See Table 1 for the classification and code of prepainted steel sheet.
4.2.2 If steel substrate not included in Table 1 in terms of application, steel substrate type, coating surface state, finish paint type, finish paint function, coating structure, surface structure of hot-dip zinc steel substrate, resistance to neutral salt spray, and accelerated weathering by ultraviolet lamp, it shall be negotiated when ordering.
Table 1 Classification and code
Classification Item Code
Application Building exterior applications JW
Building interior applications JN
Household electrical appliances JD
Others QT
Steel substrate type Hot-dip zinc steel substrate Z
Hot-dip zinc-iron alloy steel substrate ZF
Hot-dip aluminium-zinc alloy steel substrate AZ
Hot-dip zinc-aluminium alloy steel substrate ZA
Hot-dip aluminium-silicon alloy steel substrate AS
Hot-dip zinc-aluminum-magnesium alloy steel substrate ZM
Zinc electroplated steel substrate ZE
Surface state of coating Ordinary coating sheet TC
Embossed sheet YA
Printed sheet YI
Checkered sheet WA
Velvet sheet RO
Pearlescent sheet ZH
Frosted sheet MO
Finish paint type Polyester PE
Silicon-modified polyester SMP
High-durability polyester HDP
Polyvinylidene difluoride PVDF
Finish paint function Ordinary -
Self-cleaning AP
Anti-static AS
Anti-bacterial AB
Thermal-insulation AH
Coating structure Two layers of coating on the top side and one on the bottom side 2/1
Two layers of coating on the top side and two on the bottom side 2/2
Surface structure for hot-dip zinc steel substrate Minimized spangle MS
Free of spangle FS
Resistance to neutral salt spray Grade 1 S1
Grade 2 S2
Grade 3 S3
Grade 4 S4
Accelerated weathering by ultraviolet lamp Grade 1 U1
Grade 2 U2
Grade 3 U3
Grade 4 U4
5 Order contents
5.1 Contracts or orders made based on this standard shall cover the following items:
a) product name (steel sheet or strip);
b) number of the standard;
c) designation;
d) product specifications;
e) dimension and flatness precision;
f) inner diameter of steel coil (for steel strip);
g) plating weight of steel substrate;
h) surface structure of steel substrate (for hot-dip galvanized steel substrate);
i) coating structure;
j) coating surface state;
k) type and color of finish paint;
l) function of finish paint;
m) weight;
n) packaging method;
o) application;
p) other special requirements.
5.2 If dimension and flatness precision is not specified in the order contract, the products shall be supplied based on general precision.
Foreword i
1 Scope
2 Normative references
3 Terms and definitions
4 Expression method, classification and code of designation
5 Order contents
6 Dimension, shape and weight
7 Technical requirements
8 Test method
9 Inspection rules
10 Packaging, marking and quality certificate
11 Description of corrosivity of service environment for prepainted steel sheet
12 Selection of prepainted steel sheet
13 Storage, transport and loading and handling of prepainted steel sheet
14 Processing of prepainted steel sheet
15 Life to the first major maintenance and durability of prepainted steel sheet
16 Atmospheric exposure test sites for prepainted steel sheet
Annex A (Informative) Description of service environment corrosivity of prepainted steel sheet
Annex B (Informative) Selection of prepainted steel sheet
Annex C (Informative) Storage, transport and handling of prepainted steel sheet
Annex D (Informative) Processing of prepainted steel sheet
Annex E (Informative) Life to the first major maintenance and durability of prepainted steel sheet
Annex F (Informative) Atmospheric exposure test sites for prepainted steel sheet
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 standard is drafted in accordance with the rules given in GB/T 1.1-2009.
This standard replaces GB/T 12754-2006 Prepainted steel sheet.
In addition to editorial changes, the following main technical changes have been made with respect to GB/T 12754-2006:
—— normative references of GB/T 228, GB/T 1839 and GB/T 2975 are deleted, and normative reference of GB/T 8170 is added (see clause 2 of this standard and clause 2 of Edition 2006);
—— the definition of “prepainted steel sheet” is modified (see 3.1 of this standard and 3.1 of Edition 2006);
—— the designation expression method is modified, with example added (see 4.1 of this standard and 4.1 of Edition 2006);
—— designation and purpose of prepainted steel sheet are deleted (see 4.2 of Edition 2006)
—— two types of steel substrate for prepainted steel sheet are added: hot-dip aluminium-silicon alloy steel substrate and hot-dip aluminum-magnesium alloy steel substrate (see Table 1);
—— the coating sheet in the previous edition is modified into ordinary coating sheet, and coating surface states are added: checkered sheet, velvet sheet, pearlescent sheet, and frosted sheet (see Table 1 of this standard and Table 2 of Edition 2006);
—— finish paint functions of ordinary, self-cleaning, anti-static, anti-bacterial, and thermal insulation are added (see Table 1);
—— the default dimension and flatness precision grade when ordering are added (see 5.2);
—— requirements are modified for the width, length, shape of prepainted steel sheet and the thickness of its steel substrate (see 6.2 of this standard and 6.1.3 of Edition 2006);
—— regulations are added for the cases when users have requirements on the inner diameter tolerance of steel coil (see Table 2);
—— requirements are added that the mechanical property, plating property and plating weight of the prepainted steel sheet shall meet the requirements of the standards for steel substrate of corresponding designation (see 7.1.1.1);
—— the recommended nominal plating weight of each steel substrate type under different corrosive environments is deleted (Table 4 of Edition 2006);
—— the requirement is added for the color difference of coating (see 7.1.2.3);
—— the grading and test time of resistance to neutral salt spray are modified (see 7.1.2.7 of this standard and 7.3.1 of Edition 2006);
—— the grading of accelerated weathering by ultraviolet lamp is modified, and the evaluations for discoloration and dulling are added (see 7.1.2.7 of this standard and 7.3.2 of Edition 2006);
—— requirements are modified for the test of accelerated weathering by ultraviolet lamp (see 7.1.2.8 of this standard and 7.3.2 of Edition 2006);
—— the antistatic property of antistatic prepainted steel sheet and self-cleaning property of the self-cleaning prepainted steel sheet are added (see 7.1.2.9 and 7.1.2.10);
—— descriptions and technical requirements are added for checkered sheet, velvet sheet, pearlescent sheet and frosted sheet (see 7.2.3, 7.2.4, 7.2.5 and 7.2.6);
—— the sampling number for test items other than coating thickness test is modified (see Table 8 of this standard and Table 11 of Edition 2006);
—— typical atmospheric environment types corresponding to different corrosivity classes in Annex A are modified, and permissible deviations of the dimension and shape of prepainted steel sheet are deleted (see Annex A of this standard and Annex A of Edition 2006);
—— Annex B Mechanical properties of the prepainted steel sheet is deleted (see Annex B of Edition 2006);
—— Annex C Table of comparison of designations of domestic and foreign steel substrates commonly used for prepainted steel sheet is deleted (see Annex C of Edition 2006);
——Annex D Typical atmospheric environment types corresponding to different corrosivity classes is modified (see Annex A of this standard and Annex D of Edition 2006).
This standard was proposed by the China Iron and Steel Association.
This standard is under the jurisdiction of SAC/TC 183 National Technical Committee on Iron and Steel of Standardization Administration of China.
The previous editions of this standard are as follows:
—— GB/T 12754-1991 and GB/T 12754-2006.
Prepainted steel sheet and strip
1 Scope
This standard specifies the terms and definitions, designation expression methods, classification and code, order details, dimension, shape, weight, technical requirements, test methods, inspection rules, packaging, marking, and product quality certificate in connection with prepainted steel sheet and strip.
This standard is applicable to the prepainted steel sheet and strip (hereinafter referred to as "prepainted steel sheet") for building exterior and interior applications. This standard may serve as a reference for prepainted steel sheet for household electrical appliances and other purposes.
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 247 General rule of package, mark and certification for steel plates (sheets) and strips
GB/T 1766-2008 Paints and varnishes - Rating schemes of degradation of coats
GB/T 8170 Rules of rounding off for numerical values & expression and judgement of limiting values
GB/T 13448 Test methods for prepainted steel sheet
GB/T 17505 Steel and steel products - General technical delivery requirements
3 Terms and definitions
For the purposes of this document, the following terms and definitions apply.
3.1
prepainted steel sheet
the product obtained by baking and curing after continuously coating organic coating materials on the steel substrate which has been subjected to surface pretreatment
3.2
steel substrate
steel strip for coating
3.3
top side
one of the two sides of the prepainted steel sheet that has higher requirements on color, coating property, surface quality, etc.
3.4
bottom side
the other side of the prepainted steel sheet opposite to the top side
3.5
building exterior applications
applications affected by exterior atmospheric environment
3.6
building interior applications
applications affected by interior atmosphere
3.7
coating hardness
the ability of the coating to resist mechanical actions such as scratch, friction, collision and indentation
3.8
flexibility
the ability of the coating to deform with the steel substrate without damage
3.9
adhesion
the degree of firmness between coatings or between coating and steel substrate
3.10
life to the first major maintenance
the interval time between the end of manufacturing and the time when the property of the original coating degrades to the condition that its protection on the steel substrate can only be maintained through overhaul
Note: Overhaul refers to the maintenance and repair work that must be carried out on the building when the paint film becomes incomplete due to weathering or the steel substrate is perforated, including repainting, local replacement, etc.
3.11
durability
the ability of the coating to reach the specified life to the first major maintenance
3.12
weathering
the phenomenon that the coating property gradually degrades under the influence of the application environment
4 Expression method, classification and code of designation
4.1 Designation expression methods
The designation of prepainted steel sheet consists of capital letter T plus the designation of steel substrate.
Example 1: TDX51D+Z
—— representing the prepainted steel sheet with a steel substrate of designation DX51D+Z.
Example 2: TDC01+ZE
—— representing the prepainted steel sheet with a steel substrate of designation DC01+ZE.
Example 3: TS300GD+AZ
—— representing the prepainted steel sheet with a steel substrate of designation S300GD+AZ.
4.2 Classification and code
4.2.1 See Table 1 for the classification and code of prepainted steel sheet.
4.2.2 If steel substrate not included in Table 1 in terms of application, steel substrate type, coating surface state, finish paint type, finish paint function, coating structure, surface structure of hot-dip zinc steel substrate, resistance to neutral salt spray, and accelerated weathering by ultraviolet lamp, it shall be negotiated when ordering.
Table 1 Classification and code
Classification Item Code
Application Building exterior applications JW
Building interior applications JN
Household electrical appliances JD
Others QT
Steel substrate type Hot-dip zinc steel substrate Z
Hot-dip zinc-iron alloy steel substrate ZF
Hot-dip aluminium-zinc alloy steel substrate AZ
Hot-dip zinc-aluminium alloy steel substrate ZA
Hot-dip aluminium-silicon alloy steel substrate AS
Hot-dip zinc-aluminum-magnesium alloy steel substrate ZM
Zinc electroplated steel substrate ZE
Surface state of coating Ordinary coating sheet TC
Embossed sheet YA
Printed sheet YI
Checkered sheet WA
Velvet sheet RO
Pearlescent sheet ZH
Frosted sheet MO
Finish paint type Polyester PE
Silicon-modified polyester SMP
High-durability polyester HDP
Polyvinylidene difluoride PVDF
Finish paint function Ordinary -
Self-cleaning AP
Anti-static AS
Anti-bacterial AB
Thermal-insulation AH
Coating structure Two layers of coating on the top side and one on the bottom side 2/1
Two layers of coating on the top side and two on the bottom side 2/2
Surface structure for hot-dip zinc steel substrate Minimized spangle MS
Free of spangle FS
Resistance to neutral salt spray Grade 1 S1
Grade 2 S2
Grade 3 S3
Grade 4 S4
Accelerated weathering by ultraviolet lamp Grade 1 U1
Grade 2 U2
Grade 3 U3
Grade 4 U4
5 Order contents
5.1 Contracts or orders made based on this standard shall cover the following items:
a) product name (steel sheet or strip);
b) number of the standard;
c) designation;
d) product specifications;
e) dimension and flatness precision;
f) inner diameter of steel coil (for steel strip);
g) plating weight of steel substrate;
h) surface structure of steel substrate (for hot-dip galvanized steel substrate);
i) coating structure;
j) coating surface state;
k) type and color of finish paint;
l) function of finish paint;
m) weight;
n) packaging method;
o) application;
p) other special requirements.
5.2 If dimension and flatness precision is not specified in the order contract, the products shall be supplied based on general precision.
Contents of GB/T 12754-2019
Foreword i
1 Scope
2 Normative references
3 Terms and definitions
4 Expression method, classification and code of designation
5 Order contents
6 Dimension, shape and weight
7 Technical requirements
8 Test method
9 Inspection rules
10 Packaging, marking and quality certificate
11 Description of corrosivity of service environment for prepainted steel sheet
12 Selection of prepainted steel sheet
13 Storage, transport and loading and handling of prepainted steel sheet
14 Processing of prepainted steel sheet
15 Life to the first major maintenance and durability of prepainted steel sheet
16 Atmospheric exposure test sites for prepainted steel sheet
Annex A (Informative) Description of service environment corrosivity of prepainted steel sheet
Annex B (Informative) Selection of prepainted steel sheet
Annex C (Informative) Storage, transport and handling of prepainted steel sheet
Annex D (Informative) Processing of prepainted steel sheet
Annex E (Informative) Life to the first major maintenance and durability of prepainted steel sheet
Annex F (Informative) Atmospheric exposure test sites for prepainted steel sheet
