Ratio of cold-formed steel for passenger cars (GB/T6727-1986)

BUS TRAVEL VEHICLE COLD BENDING STEEL (GB/T6727-1986)

Cold-formed steel, also known as cold-formed steel or cold-formed steel, is a steel forming and processing technology of a steel member that is inclined to form a cross-sectional shape other than the cross-sectional shape formed by the hot-formed steel. It is generally pressed by a press with a tonnage of 300-3000T, and then it needs to be subjected to surface treatment such as pickling, phosphating and coating. Cold-bend steel is widely used in automotive manufacturing, home appliance manufacturing and communication equipment manufacturing.

There are various standards for cold-formed steel. GB/T6727-1986 is a national standard for cold-formed steel used for automobiles. Its scope of application covers specifications and size, technical requirements, test methods, inspection rules, packaging, marking and quality certificate. The standard specifies the technical requirements and inspection methods of cold-formed steel used for ordinary cars.

The cold-formed steel for automobiles specified in GB/T6727-1986 should meet the following requirements: (1) The chemical composition shall meet the requirements of Table 1; (2)The sizes, tolerances, shapes and sectional properties of each part shall meet the requirements of Table 2 and Table 3; (3) The mechanical properties of the steel sheet shall meet the requirements of Table 4; (4)The electrical properties of the steel sheet shall meet the requirements of Table 5; (5)The surface quality of the steel sheet shall meet the requirements of Table 6.

Table 1 Chemical composition requirements of steel sheet used for automotive cold bending

No. Chemical Composition(%)

1 %C 0.10-0.20

2 %Si ≤ 0.35

3 %Mn 0.45-0.75

4 %P ≤ 0.035

5 %S ≤ 0.035

Table 2 Sizes, tolerances, shapes and sectional properties of each part

No. Sizes and tolerances Shapes and sectional properties

1 Thickness -

Width The cross-section size and shape of the part shall be determined according to the drawings.

2 Length The section properties of each part shall meet the design requirements.

Table 3 Steel Sheet Mechanical Properties

No. Mechanical Properties

1 Tensile strength ≥ 260Mpa

Yield Strength ≥ 235Mpa

Elongation ≥ 24%

2 Impact Absorption Energy ≥ 27J

Table 4 Electrical Properties Of Steel Sheet

No. Electrical Properties

1 Tensile Strength ≥ 15kV/mm

2 Thickness Tolerance ≤ 8.0%

Table 5 Surface Quality Of Steel Sheet

No. Surface Quality

1 Visual Corrosion No visible corrosion

2 Marking and Coating Marking and coating shall meet the requirements.

GB/T6727-1986 is the technical standard for cold-formed steel used for automobiles. It provides clear requirements for chemical composition, mechanical properties and electrical properties of steel sheet and surface quality. This standard ensures the performance and quality of steel sheet used for automotive cold bending, and its implementation should be strictly enforced.

GB/T 6727-1986 Cold-Formed Steel for Passenger Motor Vehicles

GB/T 6727-1986 Cold-Formed Steel for Passenger Motor Vehicles is a Chinese national standard issued by the State Quality Supervision and Inspection Bureau. It is applicable to cold-formed steel used in the fabrication of frames, sheet, and structural components of passenger motor vehicles with a maximum gross weight of 4,500 kg or less.

This standard specifies the required chemical composition and mechanical properties of cold-formed steel. It also defines the specifications and requirements of the steel’s surface condition, finish, and dimensional inspection.

GB/T 6727-1986 requires that the chemical composition of the cold-formed steel used in the fabrication of passenger motor vehicles shall be in compliance with the values listed in table 1.

The mechanical properties of GB/T 6727-1986 cold-formed steel must meet the minimum values as specified in table 2.

The surface condition, finish and dimensional requirements of GB/T 6727-1986 cold-formed steel for passenger motor vehicles are as follows:

a) The surface of the cold-formed steel must be free from visible decarburization, cracks, slag, and other surface defects;

b) The finish of the cold-formed steel must be oiled;

c) The dimensions of the cold-formed steel, such as length and angle, must be in accordance with the applicable drawings and as measured in accordance with the methods and tolerances specified in the applicable drawings.

This standard also specifies preparation, test methods and inspection rules of GB/T 6727-1986 cold-formed steel for passenger motor vehicles.

GB/T 6727-1986 Cold-Formed Steel for Passenger Motor Vehicles is a comprehensive standard that covers the requirements for the production, supply and acceptability testing of cold-formed steel used in the fabrication of frames, sheet and structural components of passenger motor vehicles with a maximum gross weight of 4,500 kg or less. The successful implementation of this standard ensures the quality of the cold-formed steel used in the fabrication of passenger motor vehicles, ensuring the safety of the passengers.