GOST 28393-89

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  ГОСТ 28393-89

GOST 28393−89 Bars and strips of high speed steel obtained by powder metallurgy. General specifications

GOST 28393−89

Group В32

INTERSTATE STANDARD

BARS AND STRIPS OF HIGH SPEED STEEL,
OBTAINED BY POWDER METALLURGY

General specifications

RM bars and strips of high-speed steel. General specifications

GST 14 7800

Date of introduction 1991−01−01

INFORMATION DATA

1. DEVELOPED AND INTRODUCED by the Ministry of metallurgy of the USSR

2. APPROVED AND put INTO EFFECT by Decision of the USSR State Committee on management of quality and standards from 21.12.89 N 3929

3. INTRODUCED FOR THE FIRST TIME

4. REFERENCE NORMATIVE AND TECHNICAL DOCUMENTS

The designation of the reference document referenced	Item number
GOST 8.001−80*	4.2
GOST 8.326−89*	4.2
____________ * Canceled. On the territory of the Russian Federation are PR 50.2.009−94. — Note the CODE.
GOST 166−89	4.2
GOST 427−75	4.2
GOST 1051−73	2.2.4; 2.4.1.1; 5.1
GOST 1133−71	1.4; 1.5
GOST 1763−68	4.10
GOST 2216−84	4.2
GOST 2590−88	1.4
GOST 2591−88	1.4
GOST 3749−77	4.2
GOST 4405−75	1.4
GOST 5378−88	4.2
GOST 5639−82	4.11
GOST 6507−90	4.2
GOST 7417−75	1.4; 1.5
GOST 7502−98	4.2
GOST 7565−81	4.1
GOST 7566−94	2.3.1; 2.4.1; 5.1
GOST 9012−59	3.4; 2.4.1
GOST 9013−59	4.4
GOST 10243−75	4.7; 4.9
GOST 12344−88	4.1
GOST 12345−2001	4.1
GOST 12346−78	4.1
GOST 12347−77	4.1
GOST 12348−78	4.1
GOST 12349−83	4.1
GOST 12350−78	4.1
GOST 12351−81	4.1
GOST 12352−81	4.1
GOST 12353−78	4.1
GOST 12354−81	4.1
GOST 12355−78	4.1
Round bar GOST 14955−77	1.4; 1.5; 2.2.4; 2.4.1.1; 5.1
GOST 17745−90	4.1; 2.4.1.1
GOST 19265−73	4.9
GOST 21650−76	2.4.1.2
GOST 23148−98	4.1
GOST 24597−81	2.4.1.2
GOST 26653−90	5.2
GOST 26877−91	4.2
GOST 28473−90	4.1

5. Limitation of actions taken by Protocol No. 5−94 of the Interstate Council for standardization, Metrology and certification (ICS 11−12−94)

6. REISSUE


This standard applies to hot-rolled and forged bars, hot rolled, forged and calibrated rods, rods with special surface finish (hereinafter products) manufactured by hot gas-static pressing (GGP) pulverized powder with subsequent deformation of the workpieces.

Terms used in this standard, and their definitions are given in Appendix 1.

Properties and examples of application of steel is given in Annex 2.

1. BASIC PARAMETERS AND DIMENSIONS

1.1 steel grades and chemical composition for plavonia analysis shall be as given in table.1.

Table 1

	Mass fraction of element, %
Steel grade	carbon kind	cream tion		Mar Ganz	khro- mA	WOL- FRAM	Vana- Diya	Koba- lta	molyb — den	Nike- La	sulfur	Foz fora	copper	sweet — and- kind
		no more								no more
R6M5F3-MP (ДИ99-MP)	1,25- 1,35	0,60	0,50		3,80- 4,30	5,70- Of 6.70	3,10- 3,70	Not more than 0,50	5,50- 6,00	0,40	0,030	0,030	0,25	0,02
R7M2F6-MP (ДИ100-MP)	The 1.65- 1,75	0,60	0,50		3,80- 4,30	6,50- 7,50	5,50- 6,20	Not more than 0,50	1,80- 2,30	0,40	0,030	0,030	0,25	0,02
R12MF5-MP (ДИ70-MP)	1,45- 1.55 V	0,60	0,50		3,80- 4,30	11,50- 12,50	4,00- 4,60	Not more than 0,50	1,00- 1,50	0,40	0,030	0,030	0,25	0,02
R6M5K5-MP (ДИ101-MP)	Of 1.02- Of 1.09	0,60	0,50		3,80- 4,30	6,00- 7,00	1,70- 2,20	4,80- 5,30	4,80- 5,30	0,40	0,030	0,030	0,25	0,02
R9M4K8-MP (ДИ102-MP)	1,10- 1,20	0,60	0,50		3,00- 3,60	8,50- 9,50	2,30- 2,70	7,50- 8,50	3,80- 4,30	0,40	0,030	0,030	0,25	0,02
Р12МЗК5Ф2-MP (ДИ103-MP)	1,05- 1,15	0,60	0,50		3,80- 4,30	11,50- 12,50	1,80- 2,30	5,00- 5,50	2,50- Of 3.00	0,40	0,030	0,030	0,25	0,02

Note. Steel stamps letters and numbers mean: P — high speed, the number following the letter is the average mass fraction of tungsten, M — molybdenum, f — vanadium, cobalt; the numbers following the letters indicate respectively the mass percent of molybdenum, vanadium and cobalt; MG — material powder. In the designation of steel grades do not indicate mass fraction of chromium in any weight ratio.

1.2. In the finished product can be deviations in chemical composition are given in table.2.

Table 2

The name of the element	Mass fraction of element in Marche, %	Tolerance, %
Chrome	Within the standards table.1	±0,10
Tungsten	To 11.00	±0,10
	SV. 11,00	±0,15
Vanadium	To 2.00	±0,05
	SV. Of 2.00	±0,07
Molybdenum	Within the standards table.1	±0,05
Cobalt	To 0.50	±0,05
	SV. Of 4.00	±0,10

1.3. The products are made in the form of bars of circular cross section with a diameter of 2 to 150 mm square cross-section with a side of a square from 12 to 150 mm, and rectangular — strips — thickness from 6 to 100 mm and a width of 256 to 250 mm.

1.4. The form, dimensions and limit deviations of the steel products should meet the requirements:

hot rolled round and square sections — GOST and GOST 2590 2591;

forged GOST 1133;

strip — GOST 4405;

the calibrated GOST 7417;

steel with special surface finish diameter 2 to 25 mm inclusive of qualityof h9, h10, h11, h12, GOST 14955.

1.5. Steel products are classified according to the method of further processing into groups:

a — for hot forming;

b — for cold machining.

Examples of symbols:

Forged bars with a diameter of 100 mm according to GOST 1133 brand R9M4K8-MP group a:

Steel gauged round rods with a diameter of 18 mm, tolerance h11 GOST 7417, brand R6M5K5-MP, with surface quality group b, GOST 1051:

Bars with special surface finish 5 mm group of tolerance h11 GOST 14955 brand R6M5K5-MP:

2. TECHNICAL REQUIREMENTS

2.1. Products must be made in accordance with the requirements of this standard technical documentation, duly approved.

2.2. Features

2.2.1. The hardness of the steel in the annealed condition, the hardness of the samples after quenching and tempering shall meet the values given in table.3.

Table 3

	Hardness
Steel grade	after annealing		after quenching and leave HRC, not less
	NV, not more than	indentation diameter, mm, not less
R6M5F3-MP	269	3.7 V	65
R7M2F6-MP	269	3.7 V	64
R12MF5-MP	285	3,6	65
R6M5K5-MP	269	3.7 V	66
R9M4K8-MP	285	3,6	66
Р12МЗК5Ф2-MP	285	3,6	66

On demand of the consumer steel grades Р6М5ФЗ-MP, R7M2F6-MP and R6M5K5-MP is manufactured with a hardness not to exceed 255 HB (indentation diameter not less than 3.8 mm), steel stamps R12MF5-MP, R9M4K8-MP and Р12МЗК5Ф2-MP — with hardness not exceeding 269 HB (indentation diameter not less than 3.7 mm).

2.2.2. On the surface of hot-rolled and forged bars and stripes group and should not be a stress crack and grinding sunsets and sekulow, rolling captivity. Defects should be removed by gentle cutting or Stripping, the depth of which shall not exceed the tolerance on size. The width of Stripping shall be not less than six times its depth.

Permitted defects of mechanical origin (some minor risks, rabiza, prints), not to exceed half of the dimension tolerance.

On the surface of hot-rolled and forged bars and stripes group b allowed defects when their depth is determined by the control zapilovku does not exceed the norms of acceptable depth bezoperatsionnogo layer.

2.2.3. Bars with a diameter of 60 to 150 mm inclusive can be manufactured with provoslavnoy or honed surface.

The surface cleanliness must meet agreed-upon standards.

On provoslavnoy or honed surface allowed isolated defects of mechanical origin with a depth not exceeding 1% of the diameter.

Customer’s request wire diameter from 60 to 150 mm inclusive manufactured with portocannone surface requirements surface in accordance with paragraph 2.2.2.

2.2.4. The grooved surface of steel should meet the requirements of GOST 1051, steel with special surface finish — groups C, d, D GOST 14955.

Group surface finishes should be specified in the order.

2.2.5. The ends of the rods and strips should be evenly cut or cut, without burrs and shavings.

The length of the folded ends should not exceed:

1.5 diameter or thickness for steel products of diameter or thickness up to 10 mm;

40 mm — for steel products with a diameter or thickness greater than 10 to 60 mm;

60 mm — for steel products with a diameter or thickness greater than 60 mm.

For forged steel products allowed the sphericity of one end and the bevel after cutting.

It is possible to manufacture rods with centering bores at the ends (end faces) and facets.

2.2.6. In the macrostructure of steel products are not permitted delamination, foreign inclusions, cracks, liquation of sulphur in the form of lines in a closed circuit (point 3).

Allowed sulfur liquation in the form of points increased travelmasti and lines, not forming a closed contour (points 1 and 2).

2.2.7. In the kink bars and stripes after a single quenching and tempering, which provides a hardness of at least 62 HRC should not be sequin characteristic naftalinovogo fracture.

2.2.8. In the microstructure of steel is not allowed:

the micropores exceeding score 3;

chains of oxides on the borders of powder particles (oxygen liquation) in excess of score 2;

carbide heterogeneity exceeding a score of 1;

structural banding in excess of score 2;

foreign powder particles — more than one in the whole area of the cone.

2.2.9. Carbide heterogeneity in rods and strips of all sizes, macrostructure and fracture in bars, strips with a diameter or thickness up to 40 mm inclusive are provided with manufacturing technology.

2.2.10. Depth bezoperatsionnogo layer hot rolled, forged, calibrated bars and should not exceed per side:

0,3 mm 2% of diameter or thickness for diameters or thicknesses up to 20 mm, inclusive;

0.5 mm plus 1% of diameter or thickness for diameters or thicknesses exceeding 20 mm.

On honed or glubokovodnykh bars and rods with special surface finish obesplozhennym layer is not allowed.

2.2.11. Grain size of austenite after quenching should be not larger than number 10 (numbers 13 Sneijder-Graff).

2.2.12. The red hardness of steel of all grades must provide a hardness of at least HRC 58 after a four-hour tempering at the temperature: 630 °C — for steel grades Р6М5ФЗ-MP, R6M5K5-MP and R12MF5-MP; 625 °C — for steel grade R7M2F6-MP; 635 °C — for steel grades R9M4K8-MP, Р12МЗК5Ф2-MP.

2.3. Marking

2.3.1. Labeling — according GOST 7566 with additions.

2.3.1.1. All bars with a diameter or thickness greater than 40 mm shall be marked on the end or side.

For bars with diameter or thickness up to 40 mm inclusive in bundles marking should be applied to append to each bundle labels, in addition, mark at least three control rods in conjunction with staining them all with green paint showing the colors in the certificate.

2.3.1.2. Steel is additionally marked by the letters MP without the hyphen. A hyphen put in the accompanying documentation.

2.3.1.3. The marking shall contain:

trademark of the manufacturer;

stamp of technical control;

grade of steel;

the batch number and pressing.

2.4. Packaging

2.4.1. Packaging — according to GOST 7566 with additions.

2.4.1.1. Packing of bars with special surface finishing — according to GOST 14955, calibrated bars — according to GOST 1051.

2.4.1.2. When sending to a single address two or more parcels, the dimensions of which allow you to arrange transport package with dimensions according to GOST 24597, the package needs to be formed into transport packets according to GOST 21650.

3. ACCEPTANCE

3.1. Steel take parties.

The party must consist of rods or strips of the same steel grade, same size, one group, annealed in the same conditions, received more than four pressovac from various powder heats, differing in carbon, not more than 0,05% abs.

3.2. Each batch of products is accompanied by a certificate containing:

the name or trademark of the manufacturer;

the name of the consumer;

grade of steel;

the batch number and pressing;

the profile and size;

total weight;

the average mass fraction of carbon in the party and the average mass fraction of other elements standard;

the number of this standard;

the results of all tests prescribed by the standard.

3.3. To control the quality of steel products set the sample volume:

1) chemical analysis — one sample from melting of a source powder or single wire or strip from the batch;

2) sizes — 10% of bars or strips from the party, but not less than 5 pieces;

3) the hardness of the annealed steel — 15% of bars or strips from the party, but at least eight rods or strips with a diameter or thickness up to 30 mm and not less than five bars or strips with a diameter or thickness greater than 30 mm; with a smaller number of rods or strips in a party (less than eight or five) — each bar or strip;

4) the hardness after quenching with vacation and red hardness — two bars or two bars from the party;

5) surface quality all bars or strips of the party;

6) the macrostructure, one blank, one rod or one strip from the roll;

7) break — two bars or two bars from the party;

8) microstructure: micropore, oxygen liquation, carbide heterogeneity, structural banding, a foreign powder particles is one processing, one rod or one strip from the roll;

9) depth bezoperatsionnogo layer — two bars or two bars from the party;

10) the grain size of austenite — two bars or two bars from the party.

3.4. If unsatisfactory results control at least one of the indicators of re-inspection is carried out according to GOST 7566.

4. CONTROL METHODS

4.1. Selection and preparation of samples for determining the chemical composition of steel according to GOST 7565, GOST 23148; chemical analysis according to GOST 12344 — 12355 GOST, GOST 17745, GOST 28473 or other methods providing the required accuracy.

In case of disagreement between the manufacturer and user of chemical analysis carried out in accordance with listed standards.

4.2. The geometric dimensions and shape determined by means of measuring instruments according to the GOST 26877, GOST 166, GOST 427, GOST 2216, GOST 3749, 5378 GOST, GOST 6507, GOST 7502 or instruments, certified according to GOST 8.001* or GOST 8.326*.
_______________
* On the territory of the Russian Federation there are PR 50.2.009−94.

4.3. For the control according to claim 3.3 (transfer 3, 4, 6−10) from each selected unit of metal cut one sample (template) for manufacturing samples.

One sample may be used for various types of tests.

Scheme cutting, shape and dimensions of samples according to claim 3.3 (transfers 4, 8, 10) must correspond to the table.4.

Table 4

Controlled feature	The diameter or thickness of bar, mm	Scheme clippings form and sample size
Hardness after quenching and tempering The micropores Oxygen segregation	Up to 30
Carbide heterogeneity Structural banding Foreign powder particles Grain austenite	SV. 30 to 60
The micropores Oxygen segregation Carbide heterogeneity Structural banding Foreign powder particles	SV. 60
Hardness after quenching and tempering Grain austenite	SV. 60

4.4. The hardness of the steel after annealing check on the GOST 9012 after Stripping bezoperatsionnogo layer.

The test carried on one end of the rod or strip at a distance of approximately 100 mm from the end.

The number of prints should not be less than three. Each value of hardness shall be as given in table.3.

4.5. Hardness after quenching and tempering is determined according to GOST 9013 on the samples taken from the finished profile and thermally treated in the modes given in table.5. The cooled samples in oil. Leave samples two or three times with the extract for 1 h and air cooling.

Table 5

Steel grade	Temperature, °C
	hardening	holiday
R6M5F3-MP	1190−1210	540−560
R7M2F6-MP	1200−1220	550−570
R12MF5-MP	1200−1230	560−580
R6M5K5-MP	1190−1210	540−560
R9M4K8-MP	1200−1220	550−570
R12M3K5F2-MP	1210−1230	560−580

The holding time at the heating set according to the drawing.

Drawing

1 — for rectangular samples; 2 — for round samples

Control is performed on the plane perpendicular to the extrusion direction. The number of prints on each sample must not be less than three.

4.6. The surface quality of bars and stripes test without the use of magnifying devices.

If necessary, the surface is pre-sanded rings or snake.

4.7. Macrostructure of bars and stripes test without the use of magnifying devices according to GOST 10243 etching of the templates cut from finished products or intermediate blanks, with additions.

4.7.1. Surface preparation of the sample should prevent the occurrence of work hardening.

4.7.2. Samples before etching is heated to a temperature of 50−60 °C, immersed in heated to the same temperature solution. Then heated the solution with the samples to 60−70 °C and incubated for 45−90 min.

4.7.3. Evaluation of sulfur segregation is carried out on a scale of Annex 3.

4.8. The control of the fracture is carried out by inspection without the use of magnifying devices.

To control the fracture hardened and tempered is subjected to the specimens cut from the annealed finished metal.

4.9. Evaluation of the defects of the microstructure (micropores, oxygen liquation, carbide inhomogeneity, structural poloschatosti, foreign powder particles) is carried out on the samples cut at a distance of not less than 30 mm from the shear zone under the end table.4, on a plane parallel to the extrusion direction.

The samples are subjected to hardening by mode, given in table.5 for the tested grade of steel, and tempering at a temperature of 680−700 °C With exposure for at least 1 hour after warming up. Samples for the evaluation of carbide inhomogeneity, structural poloschatosti and foreign powder particles subjected to etching in a solution with a volume concentration of 0.04 cm/cmof nitric acid in ethyl alcohol.

Evaluation of micropores and oxygen segregation is carried out at a magnification of 200square cone from the surface to the mid-radius of the rod or 0.25 of the square’s side or the wide side of the strip on the scale of annexes 4 and 5.

The evaluation of structural poloschatosti is carried out at a magnification of 100on the entire area of the cone on a scale of Annex 6.

Evaluation of foreign powder particles is carried out at a magnification of 100counting method on the whole area of the cone. View foreign powder particles is given in Annex 7.

Score for micropore, oxygen segregation and structural poloschatosti is set as the arithmetic mean of the estimated worst five fields of view.

Evaluation of carbide heterogeneity is carried out on a scale N 1 GOST 19265.

4.10. Depth bezoperatsionnogo layer of steel are determined according to GOST 1763 method M2 method (Sadovsky) or M (etching in a solution with a volume concentration of 0.04 cm/cmof nitric acid in methyl alcohol).

Allowed to control depth bezoperatsionnogo layer method thermoelectric power.

Depth bezoperatsionnogo layer of the steel strip should be measured on the wide side of the strip.

If there is a dispute between consumer and manufacturer control is carried out by M2. Heat treatment of samples are recommended for the modes given in table.6.

Table 6

Steel grade	Temperature of quenching globaleval in the bath, °C	The temperature of the first cooling bath, °C	The temperature of the second bath (vacation home), °C
R6M5F3-MP	1190−1210	180−220	560−580
R7M2F6-MP	1200−1220
R12MF5-MP	1200−1230
R9M4K8-MP	1200−1220
R6M5K5-MP	1190−1210
R12M3K5F2-MP	1210−1230

4.11. The grain size of austenite is determined according to GOST 5639 comparison with the standard scale or method Sneijder-Graff on specimens cut according to table.4.

In case of dispute use method Sneijder-Graff.

Monitoring is carried out on the square section perpendicular to the extrusion direction.

Samples subjected to quenching from the temperatures given in table.5. The duration of exposure during heating is adjusted in accordance with the drawing.

4.12. To control the red hardness of steel samples heat treated in mode specified in table.5 and the relevant requirements of this standard in hardness after quenching and tempering, additionally released within four hours after heating at temperatures as specified in claim 2.2.12.

5. TRANSPORTATION AND STORAGE

5.1. Transportation and storage — by GOST 7566 with additions: transportation and storage of calibrated bars — according to GOST 1051, rods with special surface finishing — according to GOST 14955.

5.2. Preparation for sea transport should be carried out under shot 26653.

ANNEX 1 (reference). TERMS USED IN THE STANDARD AND THEIR EXPLANATIONS

ANNEX 1
Reference

Table 7

The term	Explanation
1. Pressing	The billet obtained by hot gas-static pressing capsules with powder
2. The average mass fraction of carbon in the party	The arithmetic mean value of mass fraction of carbon at the bottoms of powder made of the party of bars or stripes
3. The average mass fraction of other elements of the standard	The arithmetic mean value of the limiting mass fraction of elements given in table.1. The introduction of the average values of mass fractions of elements due to the fact that in the manufacture of pressovac the mixing of the various heats of the powder that meets the chemical composition and technical requirements
4. Powder initial melting	The powder obtained by spray-one of melting liquid metal, characterized by a homogeneous chemical composition
5. Foreign powder particles	Powder particles in the microstructure of the powder high-speed steel that is significantly different in travelmasti from the basics (particles another class of steels and alloys)

APPENDIX 2 (recommended). PROPERTIES AND EXAMPLES OF APPLICATION OF POWDER HIGH-SPEED STEEL

ANNEX 2
Recommended

Table 8

			Tool life
Steel grade	The sanding behaviour regarding steel of grade R6M5	Tensile strength at bending, MPa	Cal- factor wait bones	In comparison with steel brand	Appointment
R6M5F3-MP	1,0−1,2	3500−4400	1,3−1,8	R6M5F3	Shaped cutters, drills, reamers, core drills taps, broaches, milling cutters, shaper cutters, shavers for the treatment of low and medium alloy steels
			2,0−5,0	KH12MF	Tools for cold extruding and polygonacea alloy steels and alloys
R7M2F6-MP	1,0−1,2	3500−4400	1,3−3,0	R18	Broach, taps, end mills, reamers, profile cutters for finishing medium alloy steels, corrosion resisting steels and heat resisting steels and alloys
			3,0−5,0	KH12MF	Tools for cold deformation (cutting, upsetting, extruding) carbon and alloy steels
R12MF5-MP	1,0−1,2	3000−4000	1,5−2,0	R12MF5	Shaped cutters for machining medium alloy steel. Taps, broaches, milling cutters for finishing medium alloy, alloyed, corrosion-resistant and high-strength steels
R6M5K5-MP	1,0−1,3	3000−3800	1,5−2,0	R6M5K5	Shaped cutters, drills, reamers, core drills, milling cutters, shaper cutters, shavers for the treatment of medium-alloyed and alloy steels, corrosion resisting steels, heat resisting steels and alloys
R9M4K8-MP	1,0−1,3	3000−3700	1,5−2,0	R9M4K8	Shaped cutters, drills, reamers, core drills, milling cutters (worm, end, disc, special), shaper cutters, shavers for processing high-strength steels and heat resistant steels and alloys
R12M3K5F2-MP	1,0−1,3	3000−3500	1,5−2,0	R12M3K5F2	Shaped cutters, drills, reamers, core drills, taps, broaches, cutters (hobbing, disc, end, special), shaper cutters, shavers for processing high-strength steels, heat resisting steels and alloys

Note. Mass fraction of nitrogen in all brands of steel — 0,02−0,06%.

Fig. GRAIN SIZE AND MICROSTRUCTURE DEPENDING ON THE QUENCHING TEMPERATURE

GRAIN SIZE (a, b, d, f — 400) AND MICROSTRUCTURE (b, g, e, z — 500)
DEPENDING ON THE QUENCHING TEMPERATURE

b — the optimum quenching temperature; C, d — exceeding the maximum allowable temperature
annealing at 5−10 °C; d, e 20−30 °C; W, z is more than 30 °C

THE BASIC PROPERTIES OF STEEL DEPENDING ON THE TEMPERATURE QUENCHING AND TEMPERING

APPENDIX 3 (obligatory). DESCRIPTION OF SCALES FOR ESTIMATION OF SULFUR SEGREGATION IN THE MACROSTRUCTURE OF STEEL

APPENDIX 3
Mandatory

Sulfur segregation is a relatively bright concentric (continuous or broken) lines are metal high travelmasti.

The scale includes three photos of possible macrostructures that are measured in points. The score increases with the length and number of lines, isolation circuit:

1 — two or three lines of high travelmasti, each approximately 0.25 of the circumference;

2 — four to five lines high travelmasti, each approximately 0.5 of the circumference;

3 — two or more lines high travelmasti, one of which is in the form of a closed loop.

Fig. SCALE FOR THE ESTIMATION OF SULFUR SEGREGATION AT THE MACROSTRUCTURE

SCALE FOR THE ESTIMATION OF SULFUR SEGREGATION AT THE MACROSTRUCTURE

ANNEX 4 (required). DESCRIPTION OF THE SCALE FOR THE ASSESSMENT OF PORES IN THE MACROSTRUCTURE OF STEEL

ANNEX 4
Mandatory

DESCRIPTION OF THE SCALE FOR THE ASSESSMENT OF PORES IN THE MACROSTRUCTURE OF STEEL
(increase of 200)

The scale includes five photographs of possible microstructures, evaluated in the points:

1 — four to five point then not having a stroke location;

2 — a single weakly expressed line consisting of five or six pores;

3 — two sunken lines, consisting of three to five pores;

4 — three distinct lines of long length of from 0.25 to 0.5 of the diameter of the field of view;

5 — many distinct lines then over a length of 0.5 to 1 diameter of field of view.

Points 4 and 5 (distinct lines long) are then conditioned by contact with an inert gas (argon) into the capsule with the powder in a hot gas-static pressing as a result of leakage in the capsule (argon pores).

The main signs argon then:

1) location on the borders of powder particles in the form of multiple lines throughout the area of the cone;

2) uneven distribution over the cross section of the bar rougher lines and more — in the axial zone;

3) increase the number and length of lines with increasing temperature quenching of the samples.

Fig. SCALE for assessment of pores in the microstructure of steel

SCALE
for the evaluation of pores in the microstructure of the steel (increase of 200)

APPENDIX 5 (mandatory). DESCRIPTION OF THE SCALE FOR THE ASSESSMENT OF OXYGEN SEGREGATION IN THE MICROSTRUCTURE OF STEEL

ANNEX 5
Mandatory

DESCRIPTION OF THE SCALE FOR THE ASSESSMENT OF OXYGEN SEGREGATION
In the MICROSTRUCTURE of STEEL (increase of 200)

The scale includes three photographs of the microstructures, evaluated in the points:

1 — chain oxides on the borders of a single powder particle (one-two lines with a length corresponding to 0.5−1.0 diameter of the field of view);

2 — chain oxides in the areas of borders of several powder particles (four to six lines in length, corresponding to 0,25−0,50 diameter of field of view);

3 — chain oxides on the borders of all powder particles (the set of lines with a length corresponding to 0.5−1.0 diameter of the field of view).

Fig. SCALE for the assessment of oxygen segregation in the microstructure of steel (increase of 200)

SCALE
to evaluate the oxygen segregation in the microstructure of steel
(increase of 200)

APPENDIX 6 (mandatory). DESCRIPTION OF THE SCALE FOR THE ASSESSMENT OF STRUCTURAL POLOSCHATOSTI IN THE MICROSTRUCTURE OF STEEL

APPENDIX 6
Mandatory

DESCRIPTION OF THE SCALE FOR THE ASSESSMENT OF STRUCTURAL POLOSCHATOSTI
In the MICROSTRUCTURE of STEEL (magnification 100)

The scale consists of four photographs of the microstructures, evaluated in the points:

1 — a few mild stripes, lighter than the microstructure;

2 — one pronounced stripe, lighter than the microstructure;

3 — two or three subtle stripes, lighter than the microstructure;

4 — two-four pronounced stripes, lighter than the bulk microstructure.

The score increases with the contrast and the number of light strips representing powder particles with an increased amount of residual austenite, due to the difference in mass percentage, carbon between these particles and the base.

Fig. SCALE for assessment of structural poloschatosti in the microstructure of steel (magnification 100)

SCALE
to assess the structural poloschatosti in the microstructure of steel
(increase 100)

APPENDIX 7 (reference). DESCRIPTION AND VIEW OF FOREIGN POWDER PARTICLES IN THE MICROSTRUCTURE OF STEEL

ANNEX 7
Reference

DESCRIPTION AND VIEW OF FOREIGN POWDER PARTICLES
IN THE MICROSTRUCTURE OF STEEL
(increase 100)

Foreign powder particles in deformed steel is atravesada bands in the basic microstructure of the steel. As a rule, are accompanied by lines of the oxide.

Figure

The text of the document is verified by:
the official publication of the
Rolled steel General purpose: the security Council. Standards. -
M.: IPK Publishing house of standards, 2003