GOST 8.044-80

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  ГОСТ 8.044-80

GOST 8.044−80 State system of ensuring unity of measurements (GSI). The tips of the diamond to instruments for measuring the hardness of metals and alloys. Methods and means of verification

GOST 8.044−80

Group Т88.1*
__________________________
* In pointer «National
standards» 2004, a group Т88.2. -
Note the «CODE».

STATE STANDARD OF THE USSR

State system for ensuring the uniformity of measurements

THE TIPS OF THE DIAMOND TO DEVICES FOR MEASURING THE HARDNESS
METALS AND ALLOYS

Methods and means of verification

State system for ensuring the uniformity of measurements. Diamond indentors of the
hardness testing machines for metals and alloys. Yerification methods and means

Date of introduction 1982−01−01

DEVELOPED by the State Committee of USSR on standards

PERFORMERS

O. M. Cochin, candidate. Fiz.-Mat. Sciences; S. P. Barabanov, V. I. Kozlov

MADE with the USSR State Committee for standards

Member Of The State Committee For Standardization VI Kiparenko

APPROVED AND put INTO EFFECT by Decision of the USSR State Committee for standards of 23 December 1980 N 594
This standard applies to diamond tipped types, NK, NP and NPM churchyard 9377−74 and establishes the methods and means of their initial and periodic verifications.
The standard is consistent with the recommendations of OIML RS 4764−74 and N 2.

1. OPERATIONS AND MEANS OF VERIFICATION

1.1. During the verification needs to be performed the operation and applied means of verification specified in the table.

Notes:

1. Allowed to use other means of verification, with similar legal characteristics.

2. A periodic check is subjected to only the exemplary tips. Operating tips when operating to check just in case there is a doubt in their health (expected damage working part of diamond mounts diamond, etc.). In this case the tip must be sent for verification in main metrological center of the hardness measurement.

2. CONDITIONS VERIFICATION

2.1. The tip must be released from the lubricant, degreased with gasoline according to GOST 443−76 and rubbed the technical ethyl alcohol according to GOST 17299−78 or GOST 18300−72.

2.2. During the verification should be complied with the following conditions:

the temperature of the air in the room (20±2) °C;

relative humidity (65±10)%.

2.3. Exemplary devices-Comparators needs to be set on the tables, the design of which should provide protection from exposure to vibration.

3. VERIFICATION

3.1. External examination

Visual inspection of the nozzle includes inspection of the frame and working parts of diamond.

3.1.1. Inspection of the frames is carried out visually. The appearance of the rim of the tip must conform to the requirements of GOST 9377−74.

3.1.2. Visual inspection of the working parts of diamond is carried out using a binocular microscope under reflected light.

To inspect the top of the diamond tip set up so that the axis of the tip was a continuation of the optical axis of the microscope. Microscope focus at first on the top of the diamond, then slowly changing the focus, visiting the adjacent surface of the diamond.

For the rest of the surface of the diamond tip is mounted on the microscope stage so that the optical axis of the microscope perpendicular:

to the generatrix of the diamond cone — type NC tips;

to facet a diamond pyramid at the tip types of NP and NPM.

For inspection of the entire ferrule is rotated around its axis.

The working part of the diamond surface must meet the requirements of GOST 9377−74.

3.2. Measurement of the geometric dimensions of the rim

The diameter of the shank frame to measure it using a micrometer, lever, other sizes — caliper. Rim sizes shall be as specified in GOST 9377−74.

3.3. Measurement of the geometric dimensions of diamond

Of tips of the type NK measure the height of the working part of the diamond at its axis, a mixture of top of diamond relative to the frame axis, the vertex angle of the cone, the radius of the diamond.

Of tips types of NP and NPM measure the height of the working part of the diamond at its axis, displacement of top of diamond relative to the frame axis, the angle between the opposite faces of the pyramid, the length of the lintel on top of the pyramid.

3.3.1. To measure the height of the working part of diamond tip is mounted on the microscope stage so that its axis is perpendicular to the optical axis of the microscope. Microscope focus the reflected light on the contour of the axial section of the diamond and rotate the tip around its axis to find the border of the polished part of the diamond point that is closest to the top. The axial distance of the diamond from its top to a plane passing through this point perpendicular to the axis (i.e. the height of the working part of the diamond), measured by micrometer screw moving the table tool microscope.

The height of the working part of the diamond is specified in GOST 9377−74.

3.3.2. For measurement of the displacement of top of diamond relative to the rim tip is mounted on the tool table of the microscope so that the axis of the tip is perpendicular to the optical axis of the microscope and parallel to the axis of the micrometer screw of longitudinal displacement of the microscope table. Focusing the microscope in transmitted light on the shadow contour of the tip. Rotating the tip relative to the axis of the holder, find the rightmost position of the shadow contour of the tip and combine it with any dashed line ocular goniometric head. Remove the first indication. Rotating the tip relative to the axis of the holder, find the leftmost position of the shadow contour of the tip and rotation of the micrometer screw lateral movement of the table combine it with the previously selected dashed line goniometric head. Remove the second piece of evidence. The measurements were carried out three times. For the displacement of the working top of diamond relative to the axis of the holder be the arithmetic mean of the three polurazdeta 1 and 2nd readings. Offset the working of top of diamond relative to the axis of the rim shall be those specified in GOST 9377−74.

3.3.3. To measure the angle at the vertex of a diamond cone ferrule type SC is mounted on the tool table of the microscope so that the axis of the tip is perpendicular to the optical axis of the microscope. Focusing the microscope in transmitted light on the shadow contour of the tip corresponding to the axial cross section of a cone.

To find the value of angle is calculated on the limb the difference between the readings corresponding to successive combination of any of the radial dashed lines goniometric eyepiece head with the two forming a cone. The measurement is carried out in two axial sections parallel and perpendicular to the flatted shank of the rim of the tip. Each section performed in three dimensions.

To determine the angle in the plane of any section calculates the arithmetic mean of the three measurements. To determine the angle of the tip calculated the arithmetic mean of all six measurements in the planes of both sections.

The point angle of the diamond cone and the difference between the angles in two mutually perpendicular planes shall be as specified in GOST 9377−74.

3.3.4. To determine the angle between opposite faces of diamond pyramid tips of the types NP and NPM installed on the tool table of the microscope so that its axis is perpendicular to the optical axis of the microscope. By turning the tip about its axis to get a clear focus on two opposite edges of the pyramid in the position of greatest angle between them.

For finding the angle between two opposite edges of the limb is calculated by the difference between the readings corresponding to successive combination of any of the radial dashed lines goniometric eyepiece head with both edges. The measurements were carried out in two planes, each of which passes through two opposite edges of the pyramid and its height (axle). In each plane there are three dimensions.

Calculate the arithmetic mean of the results of all six measurements and find it (see mandatory Appendix 2) angle between opposite faces of a pyramid.

The value of the angle between the opposite faces of the pyramid shall be those specified in GOST 9377−74.

3.3.5. To measure the radius of the spherical curvature of the top diamond tip type NC set on the table microprojector so that its axis was perpendicular to the axis of the light beam of the illuminator. Shadow image of the cone of the diamond design on the mobile screen, which should be visible the outlines of possible curves with radii 0,190−0,210 mm at intervals of 0.005 mm in the scale of microprojector.

Shadow image of the diamond to check the smoothness of the conjugation of the spherical curvature with a cone and measure the radii of curvature in the same two mutually perpendicular planes in which we measured the angle at the vertex (p.3.3.3).

To determine the radius of curvature of verified tip contour of the shadow image of the diamond combine alternately with different lines on the screen. The value of the radius of curvature, indicated on the screen next to the line most closely adjacent to the contour of the shadow image of the diamond, the record calibration (see mandatory Appendix 3). To avoid subjective error, all measurements were carried out two verification officer. One of them puts on microprojector tips in random order and records in Protocol verification (mandatory, see Annex 3) the numerical values of the radii defined by the second verification officer, not knowing the sequence of installation tips.

In each of two mutually perpendicular planes is carried out at least three definitions. To determine the radius of curvature in any plane calculate the arithmetic average of the three results. To determine the radius of curvature of the tip calculated the arithmetic mean of the results of all six measurements in both planes.

The average radius of curvature of the diamond and the difference of radii of curvature in two mutually perpendicular planes shall be as specified in GOST 9377−74.

3.3.6. To measure the length of the jumper at the top of the pyramid diamond tips types of NP and NPM install on the table metallographic microscope top so that the axis of the tip is the continuation of the optical axis of the microscope. The microscope focus on the top of the pyramid and with the help of ocular micrometer to measure the length of the bridge. Length of jumper must comply with the GOST 9377−74.

3.4. Determination of the roughness of the working surface of the diamond

3.4.1. The roughness of the working surface of the diamond to estimate the average height of the irregularities and determined by sampling (5% of the span of the party), but the whole party recognize valid if the roughness parameter of each attorney tip will fit (0,25−0,5 µm).

To determine the surface roughness of the spherical curvature of the top diamond tip type NC set on an interference microscope with a top of the lens so that its axis was on the continuation of the optical axis of the microscope. Focusing the microscope, you get an interference pattern from the peak of diamond in the form of a series of closed curves inscribed in one another.

3.4.2. To determine the roughness of the surface of the conical diamond tip type NC set on an interference microscope so that the optical axis of the microscope perpendicular to the generatrix of the cone. Focusing the microscope, you get an interference pattern from a conical diamond surface in the form of a series of elongated General hyperbole asymptotes (i.e., curves that appear at the edges parallel to each other). Slowly rotating the tip around its axis, visually determine the location with the maximum surface roughness, which determine its value.

3.4.3. To determine the roughness of the faces of the diamond pyramid tips of the types NP and NPM installed on an interference microscope so that the optical axis of the microscope perpendicular to one of the facets of the diamond. Focusing the microscope, you get an interference pattern from the brink in the form of a series of parallel equally spaced straight lines. Rotating the ferrule around its axis alternately to inspect all four sides and visually determine the location with the maximum surface roughness, which determine its value.

3.5. The variance of the readings of the exemplary device with verified tips types of NP and NC readings of exemplary device with the exemplary tip

3.5.1. Deviations determined by the comparison of the testimony of the exemplary device on the same plot of exemplary measures of the 2nd category when it is installed on the device alternately in an exemplary and verified tips.

3.5.2. Prints are exemplary and verified tips when testing is applied in close proximity to each other at a distance of not less than 3 mm to eliminate the unevenness of hardness is a good measure.

Tips confide groups of 5 pieces each model should be divided into four work area. The calibration of each group is carried out in one of the working areas. The order of applying the prints shown in the diagram (see informational Annex 4).

Hardness plot of exemplary steps, used for calibration, taken to be the arithmetic mean of all the readings with a model tip.

The hardness of the plot, some device check your tip, take equal to the arithmetic mean of all readings with this tip.

3.5.3. Deviation of the readings with tip type NK determine the hardness of TR type for three exemplary measures of the MTR type with hardness values (25±5) HRC, (45±5) HRC and (65+5) HRC.

The difference between the measurement results of the device check and a standard tip should not exceed 0.5 units of hardness and differ from each other by more than 0.5 units on each of the measures.

3.5.4. Lugs type SC agreed between manufacturer and user is allowed to calibrate the exemplary devices type TRS for two exemplary measures of the type MTRS with hardness values (45±5) 30 HRN and (80±4) 30 HRN.

The difference between the measurement results of the device check and a model with lugs on each of the measures shall not exceed 1 unit hardness, and differ among themselves by more than 1 unit of hardness.

3.5.5. Deflection for push-on type of NP is determined for the exemplary devices of type of TV for three exemplary measures the hardness of MTV type with a value of hardness (450±75) HV at loads of 49.0; 294,3; 981,0 N (5, 30, 100 kgf).

The difference between the readings with the exemplary check bits, expressed as a percentage of readings with a model tip must not exceed 1% on each of the three measures and to differ by more than 1%.

3.5.6. The results of verification bits are entered into the Protocol, the form of which is given in the mandatory Annex 3.

4. THE RESULTS OF THE VERIFICATION

4.1. The results of the initial calibration bits the manufacturer prepares a stamp in the passport or the issuance of final certificate.

4.2. On tips, the ones that are suitable for verification in the main metrological centre of hardness measurement certificate in the prescribed form.

4.3. Tips not satisfying the requirements of this standard, and the application is not allowed.

ANNEX 1 (mandatory). Regulatory specifications model tips

ANNEX 1
Mandatory

Exemplary errors can be probes made according to GOST 9377−74 and the corresponding normative-technical characteristics are given below.

Lugs type SC

The vertex angle of the diamond cone (120±12)°.

The radius of the spherical curvature of the vertex of the diamond — (0,200±0,005) mm.

The displacement of the axis of the diamond relative to the axis of the rim — not more than 0.02 mm difference between the readings with a model tip and the tip is included in the state special standard of the units of hardness on Rockwell and Super-Rockwell, shall not exceed on each of the measures:

To ±0.1 units of hardness — measures the type of RTMS with a hardness of (25±5) HRC, (45±5) HRC and (65±5) HRC;

±0,2 units of hardness — measures the type of MTSR with a hardness of (45±5) HRN30 and (80±4) HRN30.

Tips-NP type

The angle between opposite faces of diamond pyramid (136±12)°.

Length jumpers on top of the diamond pyramid — not more than 0.001 mm.

The displacement of the axis of the diamond relative to the axis of the rim — not more than 0.02 mm difference between the readings with a model tip and the tip is included in the state special standard units hardness Vickers on the measures of MTV type with a value of hardness (450 ±75) HV at loads of 49.0; and 981,0 294,3 N (5; 30 and 100 kgf), expressed as a percentage of readings with a model tip that are part of the state special standard units hardness Vickers shall not exceed on each of the measures of 0.6%.

ANNEX 2 (mandatory). Translation of values of the angle between edges of a regular tetrahedron the angle between opposite faces

ANNEX 2
Mandatory

ANNEX 3 (required)

APPENDIX 3
Mandatory

Form 1

CALIBRATION PROTOCOL OF THE DIAMOND TIP

1. External examination _____________________

2. Determination of the geometric dimensions of the ferrules type SC

Form 2

1. External examination _______________________

2. Determination of the geometric dimensions of the tips of the types NP and NPM

Form 3

The variance of the readings of the exemplary device check
tips from the testimony of the exemplary device with the exemplary tip

(fill for push-on types of NC and NP)

Note. The letter a indicates the hardness is a good measure, defined using the exemplary tip before calibration;

B — hardness is a good measure, defined using the exemplary tip after verification;

In — hardness is a good measure, defined using the test tip.

ANNEX 4 (reference). LAYOUT PRINTS CHECK BITS ON A STANDARD MEASURE OF HARDNESS

ANNEX 4
Reference

In the diagram, the triangles represent the fingerprints done an exemplary tip and mugs — verified tips. Prints check bits are arranged on a circle at the same distance from the center of the print is exemplary of the tip. The procedure for applying prints each of the check bits on all circles should be the same. For example, the first and the last verified tips match the beginning and end of the circular arrows.

The numbers 1−5 in the triangles vertices represent up prints exemplary of the tip applied to the fingerprints of verified tips. Figures 6−11 in triangles vertices down the prints represent exemplary tip damage after applying all prints all verified tips.

The free area of each work station and the center of the measure can be used for testing single bits. The prints are applied in the order of their numbering:

12−16 — prints of the exemplary tip, applied at the beginning of the verification;

17−21 — check prints a single tip;

22−26 — prints of the model tip at the end of the verification.

The free area at the edges of the steps should be used for applying crimp marks which do not take into account when processing the results of verification. For stabilization of the measurements is necessary before applying control prints every tip to apply at least two blooming prints.

The text of the document is verified by:
the official publication of the
M.: Publishing house of standards, 1981