GOST 2856-79

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  ГОСТ 2856-79

GOST 2856−79 Alloys magnesium casting. Stamps (with Amendments No. 1, 2)

GOST 2856−79

Group W51

INTERSTATE STANDARD

ALLOYS MAGNESIUM CASTING

Brand

Casting magnesium alloys. Grades

ISS 77.120.20
OKP 171440

Date of introduction 1981−01−01

Resolution of the USSR State Committee for standards from September 24, 1979 N 3644 date of introduction is established 01.01.81

The expiration time limit is removed by the Resolution of Gosstandart of the USSR from 16.07.85 N 2222

REPLACE GOST 2856−68

EDITION with Amendments No. 1, 2 approved in July 1985, October 1987 (IUS 10−85, 1−88)

1. This standard applies to magnesium cast alloys for the manufacture of shaped castings.

The standard fully complies ST SEV 5734−86.

(Changed edition, Rev. N 2).

2. Depending on the chemical composition establishes the following grades: ML3, МЛ4, Ml4pch, ML5, Ml5pch, Ml5on, МЛ6, ML8, ML9, ML10, ML11, ML12, and ML15 ML19.

Note. The letters «PCH» and «he» means: PCH — high purity, it is General purpose.

3. Magnesium alloys shall be manufactured in accordance with the requirements of this standard with the chemical composition given in table.1.

Table 1

Notes:

1. Rare — earth elements included in the composition of cerium Misch metal containing not less than 45% of cerium.

2. With the simultaneous concentration of beryllium and zirconium in the alloys of МЛ4, Ml4pch, ML5, Ml5pch mass fraction of beryllium shall not exceed 0,0015%.

3. In the alloy Ml5pch mass fraction of titanium is allowed no more than 0.005%.

4. The mechanical properties of the alloys, determined on separately cast samples shall meet the requirements specified in table.2.

Table 2

Notes:

1. Designation of methods of casting:

S — sand casting;

K — chill casting;

On — casting in shell molds;

In — lost-wax casting forms;

G — casting in plaster molds;

D — die-casting.

2. Designation of the types of heat treatment:

T1 — aging; T2 — annealing; T4 — homogenization and quenching air;

T6 — homogenization, quenching in air and aging; Kzt61 — homogenization, quenching in water and aging.

3. For ML10 alloy with a mass fraction of zinc is not more than 0.5% heat treatment regime Kzt61.

4. The yield strength shall be agreed between manufacturer and consumer.


(Changed edition, Rev. N 2).

5. Determination of the chemical composition is carried out according to GOST 3240.0−76 — GOST 3240.21−76 or GOST 7728−79 or other methods that provide comparison of results.

The differences in the assessment results for determination of chemical composition determination is carried out according to GOST 3240.0−76 — GOST 3240.21−76.

Mass fraction of yttrium in the alloy brand ML19 determined in accordance with normative-technical documentation.

6. Mechanical properties of alloys determined according to GOST 1497−84.

The shape and size of the samples separately cast in sand casting, permanent mold and shell mold investment casting and plaster mold must match those in hell.1, when injection molding is hell.2.

Damn.1

Damn.2

Allowed to reduce the length of the head of the sample depending on design of the grips of the testing machine.

Samples for all kinds of casting except the molding is cast in sand molds. Allowed casting of the samples in the mold.

When injection molding is allowed cutting of specimens from cast plates with a thickness of 1.8mm, while the roughness parameter of processed surface according to GOST 2789−73должен not be less than 20 microns.

Separately cast samples experience with the mold crust. The burrs on the parting plane of the shape and location segments from the Gating system must be removed by Stripping.

Heat treatment of samples for testing the mechanical properties of the alloys should correspond to the heat treatment set for casting of these alloys.