This standard specifies the terminology, definition, basic parameters, instruments, specimens and measurement methods for the surface roughness of cold-rolled thin steel sheets (strips). This standard is applicable to the measurement of the surface roughness of cold-rolled thin steel sheets (strips) using centerline and continuous profile conversion contact instruments. GB 2523-1990 Measurement method for surface roughness of cold-rolled thin steel sheets (strips) GB2523-1990 Standard download decompression password: www.bzxz.net

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Cold rolled sheet (strip)—Measuring method for surface roughnessSubject content and scope of application
GB 2523—90
Replaces GB2523—81
This standard specifies the terminology, definition, basic parameters, instrument, specimen and measurement method for surface roughness of cold rolled sheet (strip). This standard is applicable to the measurement of surface roughness of cold rolled sheet (strip) using center line system and continuous profile conversion contact instrument. It can also be used as a reference for measuring the surface roughness of other plates and machined parts. 2 Reference standards
GB3505 Surface roughness terminology Surface and its parameters 3 Terms and definitions
The relevant terms involved in this standard, such as surface roughness, reference line, sampling length, evaluation length, least squares median line of the profile, median system, profile peak, profile valley, profile peak line, profile valley line, etc., are defined in accordance with the provisions of GB3505. This standard provides the following term definitions. 3.1 Maximum profile height Ry
The distance between the wheel magic peak line and the wheel valley line within the sampling length (1) (see Figure 1). Figure 1 Maximum wheel height Ry
3.2 Ten-point height of micro-roughness R
The sum of the average value of the absolute values ​​of the five highest profile peak heights and the average value of the absolute values ​​of the five deepest profile valley depths within the sampling length (see Figure 2).
Approved by the State Administration of Technical Supervision on July 21, 1990 5
Implemented on July 1, 1991
3.3 Arithmetic mean deviation of profile Ra
GB 2523--90
Figure 2 Ten-point height R of micro-roughness,
Arithmetic mean of the absolute value of profile deviation within the sampling length (see Figure 3). (a) ld:
Or approximately:
Figure 3 Arithmetic mean deviation of profile R.
3.4 ​​Cut-off wavelength
The wavelength in the profile spectrum that is numerically equal to the sampling length, usually taken as the upper transmission limit of the profilometer (waves with wavelengths greater than are considered as suppressed waves).
3.5 Centerline stylus profilometer
A continuous profile conversion stylus instrument that measures surface roughness based on the centerline system. 3.6 Static measuring force
The force applied by the stylus along its axial direction to the measured surface, ignoring the dynamic force generated when the stylus moves along the measured surface. 3.7 Rate of change of static measuring force
The change in static measuring force caused by a unit displacement of the stylus along its axial direction. 4 Basic parameters of measuring instrument
4.1 The nominal value of the stylus angle (radians or degrees) should be one of the following: 1. 05 rad (60°), 1. 57 rad (90°) 4.2 See Table 1 for the allowable deviation of the stylus angle.
Nominal value of stylus angle
Maximum allowable deviation of stylus angle
GB2523—90
1.05(60°)
+0.18(+10°)
0. 09(—5°)
4.3The nominal value of the stylus tip radius (um) shall be one of the following: 2, 5, 10
4.4The allowable deviation of the stylus tip radius is shown in Table 2. Table 2
Nominal value of stylus tip radius
Maximum allowable deviation of stylus tip radius
4.5Static measuring force
rad(°)
+0. 09(+5°)
0.18(-10°)
The static measuring force should ensure that the stylus is in continuous contact with the measured surface. The static measuring force and the rate of change of the static measuring force are shown in Table 3. Table 3
Nominal value of stylus tip radius, μm
Maximum value of the static measuring force of the stylus at the average height of the stylus, NMaximum value of the rate of change of the static measuring force, N/m4.6The pressure of the sensor ram on the measured surface shall not exceed 0.5N. 4.7The surface roughness R. of the sensor ram shall not exceed 0.1um. 4.8 Ram curvature radius p
Whether a single ram or a double ram (two rams arranged on a straight line perpendicular to the sensor movement direction) is used, the curvature radius on plane AA (single ram) or the curvature radius on two planes parallel to AA (double ram) shall not be less than 50 times the cut-off wavelength (see Figure 4).
4.9 Transmission characteristics in the long-wave band
GB 2523-90
Sensor movement direction
Single ram
Sensor movement direction
Double ram
Figure 4 Ram curvature radius p
The transmission characteristics in the long-wave band are determined by the nominal transmission coefficient (see Table 4 and Figure 5). The transmission coefficient K is obtained by the following formula:
Wherein: 3=Vi,
Wavelength plus the corresponding transmission coefficient equals 75%, 52
- 50. 5772/A)2
a, mm
AB=0.25 -
GB2523-90
Figure 5 Transmission characteristic curve
Cut-off wavelength
-A = 8. 0
102A, mm
5 Measurement method
5.1 Sample
GB 2523-90
5.1.1 The sample should be cut at a position that can represent the surface roughness state of the entire steel plate (strip), generally located at half the width of the plate (strip). Or as specified in relevant technical conditions.
5.1.2 The specimen is generally a square (or circle) with a side length (or diameter) of 100mm. 5.1.3 The specimen should be flat, without abrasions or scratches. There should be no rust, stains or any surface defects on the surface of the specimen. 5.1.4 The specimen should be cleaned with acetone before measurement and measured immediately. 5.2 Measurement and results
5.2.1 Before measurement, first adjust the instrument to zero so that each pointer is in the position before work. 5.2.2
Calibrate the instrument with a standard block before measurement. The error of the measured value is not more than 5%. 5.2.3
The test bench should be stable. The measurement should be carried out under dry, vibration-free and non-corrosive atmosphere conditions. 5.2.4
When measuring, place the specimen flat on the measuring bench. The direction of the stylus stroke is perpendicular to the rolling direction. 5.2.5 Determination of sampling length (or cut-off wavelength) and evaluation length. According to the range of surface roughness parameters, the sampling length and evaluation length shall be determined according to Tables 5 and 6.
Ra, um
Re, Ry um
less than or equal to
less than or equal to
sampling length 1
sampling length!
evaluation length
measure six positions on both sides of each specimen, and take the arithmetic mean value respectively, or in accordance with the relevant technical conditions. 5.2.6
5.2.7For the measurement of the upper or lower limit surface of a given surface roughness parameter, the surface area with the maximum or minimum roughness shall be selected for measurement. If one measured value exceeds the value specified in the technical documents, the surface is still qualified; the surface roughness parameter value takes the arithmetic mean of the five measured values. If more than one measured value exceeds the value specified in the technical documents, the surface is unqualified. 5.2.8 The measurement should be carried out at a temperature of 20±10℃, otherwise it should be noted in the test report. 54
Additional Notes:
GB2523-90
This standard was proposed by the Ministry of Metallurgical Industry of the People's Republic of China. This standard was drafted by Wuhan Iron and Steel Company. The main drafters of this standard are He Mingwen and Kai Jun. 55
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