GOST 26877-2008

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  ГОСТ 26877-2008

GOST 26877−2008 metal Products. Methods of measuring form deviations of

GOST 26877−2008

INTERSTATE STANDARD

Steel PRODUCTS

Methods of measuring form deviations of

Metal products. Methods of measuring form variations

ISS 77.080.20
OKP 090100

Date of introduction 2013−01−01

Preface

Goals, basic principles and main procedure of works on interstate standardization have been established in GOST 1.0−92 «interstate standardization system. Basic provisions» and GOST 1.2−2009 «interstate standardization system. Interstate standards, rules and recommendations on interstate standardization. The procedure of development, adoption, application, renewal and cancellation"

Data on standard

1 DEVELOPED by the research Institute «Ukrniimet» Ukrainian state scientific and technical center «Energostal», Interstate technical Committee for standardization MTK 327 «bars, shapes and sections"

2 MADE MTK 327 «bars, shapes and sections"

3 ACCEPTED by the Interstate Council for standardization, Metrology and certification by correspondence (Protocol No. 35 of December 30, 2008)

The adoption voted:

4 by Order of the Federal Agency for technical regulation and Metrology from August 23, 2012 252 N-St inter-state standard GOST 26877−2008 introduced as a national standard of the Russian Federation from January 1, 2013

5 REPLACE GOST 26877−91


Information about introduction in action (termination) of this standard is published published monthly information index «National standards».

Information about the changes to this standard is published in the annually published index «National standards», and the text changes and amendments — in monthly indexes published information «National standards». In case of revision or cancellation of this standard the appropriate information will be published in a monthly information index «National standards»

1 Scope

This standard establishes the methods and means of measuring equipment for measuring the deviation of the shape of steel products: blooms, slabs, billets, sheets, strips, strip, coil, bars, tubes, hot-rolled and cold-formed sections, wire rod and wire of iron and non-ferrous metals and alloys.

Terms of deviations of the form used in the standard, the relevant definitions are presented in Appendix A.

2 Normative references

The present standard features references to the following international standards:

GOST 8.050−73 State system for ensuring the uniformity of measurements. Normal conditions to perform linear and angular measurements

GOST 8.051−81 ICG. Error allowed when measuring linear dimensions to 500 mm

GOST 162−90 Gauges. Specifications

GOST 164−90 Shtangenreysmasy. Specifications

GOST 166−89 (ISO 3599−76) Calipers. Specifications

GOST 427−75 Rulers measuring metal. Specifications

GOST 577−68 indicating gages with divisions of 0.01 mm. specifications

GOST 3749−77 the Angular span of 90°. Specifications

GOST 5378−88 Protractors with Vernier. Specifications

GOST 6507−90 Micrometers. Specifications

GOST 7502−98 metallic measuring tape. Specifications

GOST 8026−92 Line calibration. Specifications

GOST 10905−86 Plate calibration and marking. Specifications

GOST 11358−89 Thickness and stenkomer indicator with a scale division of 0.01 and 0.1 mm. specifications

GOST 17353−89 devices for the measurement of deviations of form and position of surfaces of rotation

Note — When using this standard appropriate to test the effect of reference standards in the state at the corresponding index of standards, made as of January 1 of the current year and related information signs, published in the current year. If the reference document is replaced (modified), then the use of this standard should be guided by replacing (amended) standard. If the reference document is cancelled without replacement, then the situation in which the given link applies to the extent that does not affect this link.

3 measuring equipment

For the measurement of form deviations of the used universal measuring instruments, is given in Appendix B and passed the state acceptance tests, and automatic, opto-electronic, electronic and other measuring instruments, not mass-produced, contained in Appendix b and have passed the state metrological certification in the prescribed manner.

It is possible to use other types of measuring instruments with such or improved metrological characteristics, passed state acceptance tests or Metrology attestation in the state metrological services of organizations or businesses, authorized (certified) for the right to perform these works.

Measuring equipment used for measurements shall undergo verification in the prescribed manner.

4 Preparation for measurement

4.1 the Products are placed on a flat surface length less than the length of the steel products intended for measurements, such as surface plate or rack.

4.2 Metal on a flat surface should lie down freely without the influence of any external forces, such as pressure, tension, torsion, if the regulations of a particular type of rental has no other requirements.

4.3 measurement Conditions according to GOST 8.050 (paragraph 1.1).

5 procedures for measuring

5.1 Deviation from flatness and straightness are measured over the entire length of metal or a length of 1 m, if the regulations of a particular type of rental has no other requirements.

The deviation from flatness is the maximum distance from points of the real surface to the adjacent plane.

5.2 Waviness, warpage and flexure in the plane of the cross section is determined by the greatest deviation value between the flat surface and the bottom surface of the metal or between the top surface and an adjacent plane or a straight line, parallel to the flat surface.

The measurements were carried out one of the following ways:

a) with the help attached to the end or edge of steel in the vertical position of the measuring metal rulers, gauges or by using a calibration line and probe (figures 1 and 2);

,

where  — height of irregularities;

 — thickness of metal;

 — wavelength.

Figure 1

Figure 2

b) with the adjacent upper surface of the calibration line and the measurement line located vertically (figure 3);

Figure 3

C) with the adjacent upper surface of the stretched steel strings* and measuring metal ruler, placed vertically (figure 4);
________________
* Allowed to use a synthetic string that provides the required measurement accuracy. If there is disagreement of the measurement results must use steel strings.

Figure 4

d) using a dial indicator, mounted on a bracket or tripod and move parallel to the plane of arrangement of steel (figure 5).

Figure 5

The deflection in the plane of the cross section of metal products (except roll-formed profiles) is measured with a feeler gauge and check the line. Profile placed on a horizontal flat surface upward. One corner of the profile mount the probe, the thickness is equal to the allowable deviation, and it tightly pressed against the straightedge, and the other angle measure the clearance between the surface profile and straightedge (figure 6).

Figure 6

Waviness, warpage and flexure in the plane of the cross section is expressed in millimeters or percentage of the normalized length.

Wavelength is expressed in millimeters.

If necessary, the wavelength is defined as the distance between the points adjoining the surface of metal to a flat surface using a metal measuring ruler (figure 1).

5.3 the Deflection of roll-formed corrugated sections rolled in the plane of the cross section with the number of corrugations two or more measured two lines, one of which must be the measuring. Profile placed on a horizontal flat surface, one of the rulers applied to the profile so it relied on extreme corrugations (figure 7). Measuring with a ruler measure the distance between the line attached to the profile most remote from the line of the flat section of the corrugation on its axis.

Figure 7

The deflection of roll-formed corrugated sections in the plane of the cross section of the measuring line is measured in millimeters.

5.4 Torsion measured in any plane to a specified distance from the base of the cross section.

The twist is expressed in millimeters or degrees to a specified length.

Steel stack so that one of its sides in the base cross section in contact with a flat surface, and on the opposite side to measure the largest deviation perpendicular to a flat surface:

a) measure the deviation of cross section from a flat surface by using a measuring ruler or a probe (figure 8);

Figure 8

b) measure the deviation of cross section of steel from the adjacent surface with the straightedge in contact on one side with a flat surface, and a measuring ruler or a probe (figure 9). The other measuring surface of the polygon must be summed up to the contact with the surface of metal products.

Figure 9

The twist angle of the cross section of metal relative to the base cross-section (figure 9) can be measured by protractor.

in) metal shelves placed down on a flat surface length less than the length of the profile and measure the deviation from a flat surface on the segment equal to the standardized length or in any segment of length not less than 1 m using a Vernier caliper or a feeler gauge (figure 10).

Figure 10

g) to measure the twisting cold-formed sections around the longitudinal axis of the profile stack supporting surface on a flat surface (figures 11 and 12). One end of the profile is pressed against the supporting surface to the flat surface and on the opposite end measure the greatest amount of variation perpendicular to the flat surface.

Figure 11

Figure 12

For the corrugated profile of the support surface is the distance between the outermost corrugations or shelves; corner — flange width; channel, trough, z, a closed box-shaped and C-shaped profiles — the height of the profile wall. To measure the twisting sections of the support surface are planar areas of the substrate profile limited to two places of bending.

For wavy profile of the reference surface is the distance between the axes of symmetry of extreme waves.

5.5 thickness variation defined as the difference between the maximum and minimum thicknesses of steel products or parts at a predetermined distance from the end or edges (figures 13 and 14).

Figure 13

Figure 14

The rate is measured with a micrometer, caliper, thickness gages and santomero and expressed in millimeters.

5.6 Convexity and concavity determine the largest deviation between the surface metal and the surrounding plane in any cross section along the length of the product (figure 15).

Figure 15

Convexity and concavity is measured by means of a square and a measuring ruler or a probe and expressed in millimeters.

5.7 the Curvature (camber) is defined as the largest deviation between the surface of the metal and applied a ruler or stretched smooth steel string without twists and kinks (figures 16 and 17).

Figure 16

Figure 17

The curvature (camber) is measured by a measuring ruler or a probe and expressed in millimeters in standard length.

The curvature of the curved corrugated sheet profiles in the longitudinal direction is measured using a string and a measuring ruler on Goram. For the measurement profile is laid on a horizontal flat surface and pull the steel string, the length of each corrugation alternately.

The maximum value of deviation is a measure of the curvature in the longitudinal direction (figure 18).

1, 2 — application strings

3 — a string

the curvature of the profile

Figure 18

The curvature of the curved corrugated sheet profiles in the longitudinal direction is measured in millimeters.

5.8 the Skew shelves define a maximum deflection of shelves of metal from the horizontal and vertical surfaces.

The products have so that one of its sides in the base cross section in contact with a flat surface.

Measure the deviation of cross section of steel along the horizontal or vertical plane from the adjacent surface with the straightedge in contact on one side with a flat surface, and measuring with a metal ruler or template (figure 19). The other side of the polygon must be summed up to the contact with the surface of metal products.

Figure 19

The deflection of the shelves from the horizontal is determined using a calibration ruler, probe, or a measuring ruler (figure 20).

Figure 20

The skew shelves are measured in millimeters.

5.9 Ovality and cut variety of non-compliance with the forms of circular cross-section metal products. Ovality is defined as half the difference of the greatest and smallest diameters in the same cross-section (figure 21).

Figure 21

The rate is measured with a micrometer or caliper (in millimeters).

Cut measure kruglaia or in the pass-through ring. When measuring the ring diameter must be equal to the diameter of the surrounding circle (figure 22). The cut measured in millimeters.

Figure 22

5.10 the Deviation from the value of the specified angle is defined as the difference between the actual angle and specified (figure 23).

Figure 23

The deviation angle measured by protractor or by means of a square and a measuring ruler or a probe (in degrees or millimeters).

5.10.1 Combichrist as one of the types of deviations from the angle determined in two ways: by the difference of the diagonals in one cross-section (figure 24A) or a deviation from the straight angle (figure 24B).

Figure 24

Combichrist measure protractor, measuring ruler or caliper and expressed in degrees or millimeters.

5.10.2 Widening as one of the types of deviation from Squareness is defined as the difference between the widths of the profile cross section.

The broadening of the measuring line is measured and expressed in millimeters.

,

where and is the width of the profile

Figure 25

5.11 Cosine of the cut is defined as the largest deviation from the plane of the end steel products to each plane perpendicular to the longitudinal planes of metal and passing through the outermost point of the edge of the end face or the angle between them (figure 26).

Figure 26

To determine the skew of the cut corrugated metal it is placed on a flat surface and using a measuring ruler and template (figure 27A) was inserted into the corrugations so that the guide line of the template was pressed against the lateral branches of corrugation, a line pattern perpendicular to the rail, in contact with the extreme ends of one of the shelves steel products, define the measuring line deviation between the line pattern and the outermost point of the profile (figure 27B).

and

b

Figure 27

Allowed cosine of cut flat steel products (sheets, strips and slabs) defined as the difference of the diagonals provided that the metal at one end has a right angle (figure 28a). In the absence of a right angle with at least one end of metal cosine of the cut is defined as half the difference of its diagonals (figure 28B).

Figure 28

Reza cosine measure measuring ruler, tape measure and a set square or a protractor and expressed in millimeters or degrees.

5.12 the Deviation from symmetry is defined as the difference between the distances to the extreme opposite points lying on the surface of steel products from the wall profile (figure 29).

,

where is the width of an elongated flange

 — shortened the width of the flange

Figure 29

The deviation from symmetry determine the measuring line by means of a square or other measuring instruments providing the required accuracy.

5.13 Blunting of the angles or corners radiused profile is measured as the distance from the vertex of the angle formed by the intersection of adjacent faces, to the borders of the scene.

Recommended control methods for blunting the corners of the rental given in Annex G.

5.14 is basically a telescoping of the roll is measured using two rulers, one of which should be measuring, according to the scheme presented in figure 30.

 — band width;  — basically a telescoping

Figure 30

Annex a (mandatory). Terms of deviations of the form used in the standard, with their respective definitions

Appendix A
(required)

A. 1 General concepts

A. 1.1 reference surface: the Surface whose profile is placed on a flat surface for measurement.

A. 1.2 the basic cross-section Set by the normative documents the cross-sectional shape of steel products.

A. 2 Terms and definitions of the deviation of the shape of steel products is presented in table A. 1.


Table A. 1

Appendix B (recommended). The list of universal measuring instruments for measuring the deviation of the shape of metal

Appendix B
(recommended)

Table B. 1

Annex b (recommended). Automatic tool measuring technology (ASIT), not mass-produced

The App
(recommended)

Table B. 1

Annex G (recommended). Methods to control the blunting of the angles of a rental

Appendix D
(recommended)

To control the blunting of the external corners of a square (rectangle) with a side (thickness) to 50 mm and hexagon use templates in the form of a square, made in accordance with figures G. 1 and G. 3.

Templates with slots, the width of which corresponds to the blunting of the angles of a square (rectangle) and the hexagon, closely applied to the corner of the corresponding profile.

The width of the slot of the template , mm, to control the external corners of a square (rectangle) is determined by the formula

or , (1)

where is the magnitude of the blunting of corners.

The magnitude of blunting of the external corners of a square (rectangle) shall not exceed the values established by the regulatory document for steel. The results of the calculation of the width of the slot pattern and the recommended depth of the slot is given in table G. 1.


Table G. 1

In millimeters

For a square (rectangle) with a side (thickness) of more than 50 mm in order to control the magnitude of the blunting of the angles, use the device made in the form of a square, to which is welded a caliper in accordance with figure 2. On the inside corner of the fixture cause division from 5 to 30 mm.

Figure G. 1

Figure 2

The magnitude of blunting of the angles controlled by a Vernier caliper, the measured value of which shall not exceed the permissible value of the blunting of the angles calculated by the formula

(2)

where is the magnitude of the blunting of the angles according to the normative document for the products.

Figure 3

The width of the slot of the template , mm, to control the blunting of the corners of the hex of the rental is determined by the formula

(3)

where is the magnitude of the blunting of the angles according to the normative document for the products.

The results of the calculation of the width of the slot of a template recommended depth of the slot and the length of the pattern is given in table 2.


Table 2

In millimeters

Blunting of the corners of the hex rent control, applying the template to the hexagon (figure G. 4).

Figure 4