JPH0712956U - Vickers hardness tester with high measurement accuracy - Google Patents

Abstract

(57) [Summary] [Purpose] It is an object to provide a Vickers hardness meter capable of clearly detecting the size of an indentation portion by a Vickers indenter. [Structure] In addition to the observation light, an oblique-angle light irradiation lamp is provided to direct the indentation portion by the Vickers indenter, and the oblique-angle light is emitted to the indentation portion separately from the observation light. [Effect] The edge of the indentation becomes clear.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to a Vickers hardness tester for measuring hardness of various materials.

[0002]

[Prior art]

 The Vickers hardness test, which is carried out to check the hardness of the material, is performed by sanding the hardness measurement surface as needed, mirror polishing with alumina, etc., or by chemical and electrolytic polishing to remove processing strain on the surface. It is a common method to apply an appropriate weight to the surface with a pressure roller after smoothing, and to evaluate the hardness of the object to be measured by the size of the indentation made as a result.

[0003]

[Problems to be solved by the device]

 However, the indentation formed by such a method causes undulations due to plastic deformation around the indentation depending on the object to be measured, and it is difficult to correctly determine the size of the indentation, and there is a problem in hardness measurement accuracy. It often happens. There was a problem with the measurement accuracy especially when the indentation was small, such as when the measured object was hard or when the measurement load was small.

Therefore, the present invention has an object to solve the above problems and provide a Vickers hardness meter capable of performing a hardness test with high reliability.

[0005]

[Means for Solving the Problems]

 The present invention for solving the above-mentioned problems can accurately determine the edge of the indentation by irradiating the indentation portion formed by the Vickers indenter with the oblique light from both sides of the indentation in addition to the observation light. As mentioned above, it is a Vickers hardness tester equipped with a new irradiation lamp.

[0006]

[Action]

 Hereinafter, the present invention will be described in detail. As shown in Fig. 2, with a Vickers hardness tester that is commonly used at present, the indentation 2 made on the DUT 1 is directed to both sides of the indentation 2 from the newly installed illumination lamp 4 in addition to the observation light 3. The oblique angle light 5 is applied so that the edge of the indentation can be clearly observed. The illumination lamp is not particularly limited, but it is desirable that the illumination light be as thin as a beam and that the direction of the light source be adjustable so that the light source can accurately illuminate the opposite surface of the indentation. The indentation is then accurately measured in size.

According to the present invention as described above, even if the surroundings of the indentation are deformed by plastic deformation, the indentation portion is illuminated more emphasized, so that the edge portion is clearly observed and the size of the indentation can be reduced. It is possible to measure accurately, and it is possible to accurately determine the hardness of the measured object. Therefore, the reliability of the test results obtained is extremely high. It is clear that the hardness measurement results obtained in this way are extremely useful for developing new materials and designing equipment and machine tools.

[0008]

【Example】

 Next, an embodiment of the present invention will be described. A test piece (diameter 10 mm × length 75 mm) of a low alloy steel material was heat-treated at a high temperature (heating rate: 5 ° C./second, temperature: 950 ° C., heating time: 60 seconds) and cooled with water. The relationship between the cooling rate and the hardness between 800 and 500 ° C. during the cooling process at that time is shown by the Jominy curve in FIG. As a comparative example of the present invention, the hardness measured by the current hardness tester is shown. That is, the hardness test result of the present invention shows a highly reliable measurement result with very little variation as compared with the result measured by the current tester. It is considered that such a result is due to the effect that the edge of the indentation was clearly observed by the illumination with the newly installed oblique light.

[0009]

[Effect of device]

 As described above, according to the present invention, in addition to the observation light, a new illumination device is attached to the hardness meter from both sides of the indentation, and oblique angle light is applied to the indentation portion to illuminate the indentation made by the indenter more strongly As a result, the blurring of the indentation edge due to plastic deformation around the indentation becomes clear, and as a result, highly reliable test results can be obtained.

[Brief description of drawings]

FIG. 1 is a Jominy curve diagram showing an embodiment of the present invention.

FIG. 2 is a schematic view of an illumination light by the lighting device of the present invention.

[Explanation of symbols]

 1 DUT 2 Indentation 3 Observation light 4 Illumination light 5 Oblique light

Claims (1)

[Scope of utility model registration request] 1. An oblique light irradiation lamp is additionally provided in addition to the observation light by directing an indentation portion by a Vickers indenter when hardness is measured using a Vickers hardness meter.
Vickers hardness tester with high hardness measurement accuracy.