Automatic gauge gauge in manual measurement of elongation after break (A) - Database & Sql Blog Articles

Automatic gauge for manual measurement of elongation after break (

A

Application in)

-------

Based on

GB/T 228.1

Automatic gauge, including automatic marking machine and automatic gauge length marking machine

The basic features of the automatic gauge:

1, One-button operation, automatic operation

2, Specify the gauge length and the interval to perform effective dot or line

3, The force of the tapping force or the action on the knife can be adjusted to minimize damage to the specimen.

4, Precision transmission components plus intelligent control, high precision

5, Intuitive, easy to operate, high efficiency

6, Production of sample gauge line under the requirements of relevant sample standards

Manually measure elongation after break (

A

The main points:

1, After the break, the two samples are on the same axis.

2, Proper cross-section

3, Direct measurement condition

4, Displacement measurement (appendix H)

5, Elongation at break

5%

The following material measurements (appendix G)

6, Representation method and conversion

7, Rounding interval

Original gauge length mark:

Mark the original gauge length with a small mark, a thin line, or a fine ink line, but do not mark it with a gap that causes premature breakage.

Note:

OH5300

The force on the knife can be adjusted, and the precision knife can be used to achieve fine and clear gauge line. At the same time, there can be a matching knife with different hardness. For special samples, the ink line can be coated on the surface of the sample, and the corresponding knife and the force on the knife can be adjusted to achieve the ink surface of the sample. Thus, a fine gauge line is obtained to achieve zero damage to the sample.

OD5350

The force of the nod can be adjusted, and a small identification point can be produced on the surface of the sample without causing premature breakage.

For proportional samples, if the difference between the calculated value of the original gauge length and its marked value is less than

10% L₀

, the calculated value of the original gauge length can be pressed

GB/T8170

Repair to the nearest

5mm

Multiples. The mark of the original gauge length should be accurate to

±

1%

. Parallel length

L_e

It is much longer than the original gauge length, such as a machined sample, which can be marked with a series of nested original gauge lengths. In the case of drought, a line parallel to the longitudinal axis of the sample can be drawn on the surface of the sample, and the original gauge length is marked on this line.

Note: Tianjin Outlet's full range of standard gauge punching machines or gauge length marking machines can be realized.

5mm

Interval dot or line.

For the mark of the nested gauge length,

OH5300

Self-standard gauge and

OD5350

The automatic gauge length punching machine can quickly mark the specimen nesting gauge length.

A

: residual elongation of the gauge length after breaking (

L_u-L₀

) with the original gauge length (

L₀

Percentage of ratio

Determination

A

The fractured parts of the specimens should be carefully mated together so that their axes are on the same line, and special measures are taken to ensure that the specimens are broken after the specimens are properly contacted. It is especially important for samples with small cross-sectional areas and low elongation samples.

Note:

ODC1350

After the double-station break gauge length measuring table can easily realize the axial docking of the sample after the break, the correcting of the fracture is the correct occlusion and the elimination of the gap (pre-tightening), improving the measurement accuracy and the convenience of measurement.

The amount of elongation after breakage should be measured using a gage or measuring device with sufficient resolution (

Lu-L0

), and to the degree of ±

0.25mm

method

1

: Manual measurement method

Before the test, mark the sample gauge length at the center of the parallel length of the sample

L₀

, accurate to ±

1%

. Marked within the gauge length

N

Equal intervals.

After breaking, the broken parts of the sample are carefully mated together so that their axes are on the same straight line, and special measures are taken to ensure that the broken gauge length of the sample is determined after proper contact of the broken part of the sample.

If the distance between the specimen breaks from the nearest gauge mark ≥

1/3 L₀

When the extension ratio is greater than or equal to the specified minimum value, the distance between the two markers is directly measured.

L₀

.

If the specimen breaks between the two punctuation marks, but the distance from the nearest gauge mark <

1/3 L₀

At the time, the "displacement method" can be used to measure the elongation after break.

See below

a

,

b

Shown.

If the distance between the break of the specimen and the nearest gauge mark is <

1/3 L0

However, when the elongation after break is greater than or equal to the specified minimum value, the "displacement method" can also be used to measure the elongation after break.

OD5350

Automatic marking machine and

OH5300

Automatic gauge length marking machine, effective indexing or scribing of indicator distance and interval, fast implementation of gauge length

N

Equally marked. Regardless of the gauge and form of the specimen, especially the small gauge specimen, the threaded end connection specimen, the step specimen, etc., can effectively ensure that the specimen is not damaged.

among them

OH5300

The gauge length and interval of the automatic gauge distance marking machine can be set freely (whether it is a decimal or an integer)

Elongation at break

5%

The following materials

A

Determination

For low-ductility materials, the measurement of the elongation at break of some materials is difficult to be accurate by the usual method, so the appendix is used.

G

The special methods provided are as follows:

Make a small mark at one end of the parallel length before the test. Use the gauge adjusted to the gauge length to mark the circle as a circle. After breaking, the broken specimen is placed on a device, and axial force is preferably applied by means of a screw so that it is firmly butted together during measurement. With the original center as the center, draw the second arc with the same radius. Measuring the distance between two arcs with a tool microscopic or other suitable instrument is the elongation after the break, accurate to the

0.02 mm

. To make the scribe line clearly visible, apply a layer of dye before the test.

OD5350

Automatic two-point function of the marking machine

OH5300

The gauge length and interval of the automatic gauge length marking machine can be set arbitrarily (set the gauge length and interval to equal, that is, the number of copies is

1

) can easily achieve the initial

L₀

Mark.

For proportional samples, if the scale factor

k

Not for

5.65

,symbol

A

The following scale should be attached to the scale factor used, for example

A11.3

For non-proportional samples, symbols

A

The original gauge length used in the following description shall be attached to the millimeter (

Mm

), for example,

A80mm

Fixation of sample result values

The performance result values determined by the test shall be revised in accordance with the requirements of the relevant product standards. If no specific requirements are specified, the contract should be amended to

0.5%

Elongation after break (

A

Conversion

standard

20.3

Article stipulates that the elongation after break can be measured on a fixed gauge length by agreement before the test, and then converted into the elongation after break of the proportional gauge length using a conversion formula or a conversion table (for example, it can be used)

GB/T 17600.1-1998

"Elongation of steel elongation

First

1

Part: Carbon steel and low alloy steel

GB/T 17600.2-1998

"Elongation of steel elongation

First

2

Part: Austenitic steel.

Only when the gauge length, cross-section shape and area are the same, or when the scale factor

k

At the same time, the elongation after break is comparable.

Elongation conversion is not strictly accurate, there is a certain error, and can only be used if both parties agree.