GOST 18227-98

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  ГОСТ 18227-98

GOST 18227−98 (ISO 2740−86) sintered metal Materials, excluding hardmetals. Samples for tensile tests

GOST 18227−98
(ISO 2740−86)
Group B59

INTERSTATE STANDARD

SINTERED METAL MATERIALS, EXCLUDING HARDMETALS

Samples for tensile tests

Sintered metal materials (excluding hardmetals).
Tensile test pieces

ISS 77.160
AXTU 1909

Date of introduction 2001−07−01

Preface

1 DEVELOPED by the Intergovernmental Committee for standardization MTK 150; Institute for problems of materials science im. I. N. Frantsevich of NAS of Ukraine

SUBMITTED to the State Committee of Ukraine for standardization, Metrology and certification

2 ADOPTED by the Interstate Council for standardization, Metrology and certification (minutes N 13 dated 28.05.98)

The adoption voted:

3 this standard is a full authentic text of international standard ISO 2740−86 «sintered metal Materials, excluding hardmetals. Samples for tensile tests» and contains additional requirements that reflect the needs of the economy

4 Resolution of the State Committee of the Russian Federation for standardization and Metrology dated December 19, 2000 N 384-St inter-state standard GOST 18227−98 (ISO 2740−86) introduced directly as a state standard of the Russian Federation from July 1, 2001

5 REPLACE GOST 18227−85

1 Purpose

This standard specifies:

— dimensions of the die cavity of the moldused for the manufacture of pressing and sintering of the samples for the tensile test, and some sample sizes obtained from this matrix.

— dimensions of specimens for tensile tests made by the mechanical processing of sintered materials.

2 Scope

This standard applies to all sintered metals and alloys, except the carbide, and materials based on refractory compounds.

Additional requirements that reflect the needs of the economy, in italics.

3 Normative references

This standard uses the reference to GOST 1497−84 (ISO 6892−84) Metals. Test methods tensile

4 specimen preparation for tests

4.1 Compacting and sintering of samples for testing

4.1.1 Requirements matrix

The size of the cavity of the matrix used to manufacture the sample for test should conform to figure 1.

Figure 1 — View of the die cavity depending on the material of the mold, and its size

In millimeters

Figure 1 — View of the die cavity depending on the material,
made the mold, and its size

It is preferable that the matrix was made of hard alloy. Its surface treatment (surface treatment of the walls of the molding cavity) to ensure the normal (ordinary) conditions of pressing, i.e. pressing should be bilateral.

It is possible to produce the matrix of the tool steel. Figure 1 shows the matrix of hard alloy and tool steel.

4.1.2 Requirements sample for test

The thickness of the sample for testing must be from 5.4 to 6.0 mm. If necessary, allocate it marks centerline and in different directions symmetrically from the center distance 25 mm. within these labels, the thickness of the sample for testing should not differ by more than 0,04 mm. Method of applying labels that identify the calculated length of the sample should not affect the characteristics of the stretching.

Clips of the specimen can be grooved.

Samples for test shall be made two-way pressing, followed by sintering under the same conditions as the finished product.

On the surface of the samples shall be free of protuberances, dents, cracks, burrs, delaminations, inclusions, cavities and mechanical damage visible during visual inspection without the use of magnifying tools.

4.2 machined samples for test

4.2.1 machined samples for test should have a cylindrical working portion with dimensions corresponding to GOST 1497.

If the diameter of the working part of the specimen for testing is less than 4 mm, it is necessary to establish and specify that the results of the sample cannot be compared with the results obtained on samples with large diameters.

For sintered products it is recommended to use the sample for testing with two transition pieces at each end. The radius of the working portion with the transition area of the head of the sample should be from 1.5 to 5 mm (figure 2).

Figure 2 — the sampler Head with a transitional phase

Figure 2 — the sampler Head with a transitional phase

Place tenderloin pieces for samples from finished products, the types and modes of machining should be specified in the normative document on the specific product.

4.2.2. Allowed testing of flat samples manufactured by machining from a sheet of flat material obtained by rolling metal powders and subsequent sintering in the form of finished products.

Dimensions flat specimens must comply with GOST 1497. The methods and types of mechanical processing of flat samples, as well as the size of these samples, if they do not meet the requirements of GOST 1497, needs to be specified in regulations for a specific product.

5 Additional information

Since the test results may depend on the matrix material, it is necessary to describe the Protocol of the test. The Protocol must be specified as well as was made a sample for test (pressing and sintering, or machining).

Other data needed for the test shall be agreed between the customer and the manufacturer or indicated in the regulatory document for a specific material (product).

Samples should be tested in tension according to GOST 1497.