GOST 21357-87
GOST 21357−87 Castings, cold-resistant and wear-resistant steel. General specifications
GOST 21357−87
Group В83
INTERSTATE STANDARD
THE CASTING OF COLD-RESISTANT AND WEAR-RESISTANT STEEL
General specifications
Cold-resistant and wear-resistant steel castings. General specifications
OKP 41 1240
Date of introduction 1988−07−01
This standard applies to the casting of cold-resistant and wear-resistant steel (further — casting) parts for the machines in climatic design CL according to GOST 15150.
INFORMATION DATA
1. DEVELOPED
The Ministry of higher and secondary special education of the RSFSR
The Ministry of Railways of the USSR
Academy of Sciences of the USSR
The Ministry of ferrous metallurgy of the USSR
The Ministry of higher and secondary specialized education of the USSR
The Ministry of coal industry of the USSR
2. INTRODUCED by the Ministry of higher and secondary special education of the RSFSR
3. APPROVED AND put INTO EFFECT by Decision of the USSR State Committee for standards from
4. REPLACE GOST 21357−75
5. REFERENCE NORMATIVE AND TECHNICAL DOCUMENTS
| The designation of the reference document referenced |
The number of the paragraph, subparagraph, enumeration, applications |
| GOST 977−88 |
3.7, 4.5 |
| GOST 1497−84 |
4.6 |
| GOST 3212−92 |
2.1 |
| GOST 7565−81 |
3.6, 4.3 |
| GOST 9012−59 |
4.8 |
| GOST 9454−78 |
4.7 |
| GOST 12344−88 |
4.4 |
| GOST 12345−2001 |
4.4 |
| GOST 12346−78 |
4.4 |
| GOST 12347−77 |
4.4 |
| GOST 12348−78 |
4.4 |
| GOST 12350−78 |
4.4 |
| GOST 12351−81 |
4.4 |
| GOST 12352−81 |
4.4 |
| GOST 12354−81 |
4.4 |
| GOST 12355−78 |
4.4 |
| GOST 12356−81 |
4.4 |
| GOST 12357−84 |
4.4 |
| GOST 12360−82 |
4.4 |
| GOST 12361−82 |
4.4 |
| GOST 15150−69 |
Chapeau, 5.6 |
| GOST 22536.0−87 |
4.4 |
| GOST 22536.1−88 |
4.4 |
| GOST 22536.2−87 |
4.4 |
| GOST 22536.3−88 |
4.4 |
| GOST 22536.4−88 |
4.4 |
| GOST 22536.5−87 |
4.4 |
| GOST 22536.7−88 |
4.4 |
| GOST 22536.8−87 |
4.4 |
| GOST 22536.9−88 |
4.4 |
| GOST 22536.10−88 |
4.4 |
| GOST 22536.11−87 |
4.4 |
| GOST 22536.12−88 |
4.4 |
| GOST 26645−85 |
2.1 |
| GOST 27809−95 |
4.4 |
6. Resolution of Gosstandart No. 646 from
7. REISSUE
1. BRAND
1.1. Castings are made from steel grades 08G2DNFL, 12KHGFL, 14KH2GMRL, 20GL, 20FTL, 20KHGSFL, 25KH2NML, 27KHN2MFL, 27KHGSNMDTL, 30GL, 30KHG2STL, 30KHL, 35KHMFL, 35HML, 110G13L, 110G13KHBRL.
The appointment for cold-resistant grades of steel castings are given in Appendix 1.
Chemical composition of steel for castings must conform to table.1.
Table 1
| Mark steel |
The content of chemical elements in percentage by mass percentage | ||||||||||
| Carbon rod |
Mar Ganz |
Cream tions |
Chrome | Nickel | Mo- lib- den |
Vana- DIY |
Copper | Titan | Bor | Nio- Biy | |
| 08G2DNFL |
0,05- 0,10 |
1,30- 1,70 |
0,15- 0,40 |
Not more than 0.30 |
1,15- 1.55 V |
- | 0,02- 0,08 |
0,80- 1,10 |
- | - | - |
| 12KHGFL |
0,10- 0,16 |
0,90- 1,40 |
0,30- 0,50 |
0,20- 0,60 |
Not more than 0.30 |
- | 0,05- 0,10 |
Not more than 0.30 | - | - | - |
| 14KH2GMRL |
0,10- 0,17 |
0,90- 1,20 |
0,20- 0,42 |
1,40- 1,70 |
Not more than 0.30 | 0,45- 0,55 |
- | Not more than 0.30 | - | At the races- couple 0,004 |
- |
| 20GL |
0,17- 0,25 |
1,10- 1,40 |
0,30- 0,50 |
Not more than 0.30 | Not more than 0.30 |
- | - | Not more than 0.30 | - | - | - |
| 20FTL |
0,17- 0,25 |
0,80- 1,20 |
0,30- 0,50 |
Not more than 0.30 | Not more than 0.30 |
- | 0,01- 0,06 |
Not more than 0.30 | 0,010- 0,025 |
- | - |
| 20KHGSFL |
0,14- 0,22 |
0,90- 1,30 |
0,50- 0,70 |
0,30- 0,60 |
Not more than 0.40 |
- | 0,07- 0,13 |
Not more than 0.30 | - | - | - |
| 25KH2NML |
0,22- 0,30 |
0,50- 0,80 |
0,20- 0,40 |
1,60- 1,90 |
0,60- 0,90 |
0,20- 0,30 |
- | Not more than 0.30 |
- | - | - |
| 27KHN2MFL |
0,23- 0,30 |
0,60- 0,90 |
0,20- 0,42 |
0,80- 1,20 |
The 1.65- Of 2.00 |
0,30- 0,50 |
0,08- 0,15 |
Not more than 0.30 |
- | - | - |
| 27KHGSNMDTL |
0,22- 0,31 |
0,90- 1,50 |
0,70- 1,30 |
0,70- 1,30 |
0,70- 1,20 |
0,10- 0,30 |
- | 0,30- 0,50 |
0,03- 0,07 |
- | - |
| 30GL |
0,25- 0,35 |
1,20- 1,60 |
0,20- 0,50 |
Not more than 0.30 | Not more than 0.30 | - | Not more than 0.30 |
- | - | - | |
| 30KHG2STL |
0,25- 0,35 |
1,50- 1,80 |
0,40- 0,80 |
0,60- Of 1.00 |
Not more than 0.30 | - | - | Not more than 0.30 |
0,01- 0,04 |
- | - |
| 30KHL |
0,25- 0,35 |
0,50- 0,90 |
0,20- 0,50 |
0,50- 0,80 |
Not more than 0.30 | - | - | Not more than 0.30 |
- | - | - |
| 35KHMFL |
0,30- 0,40 |
0,40- 0,60 |
0,20- 0,40 |
0,80- 1,10 |
Not more than 0.30 | 0,08- 0,15 |
0,06- 0,12 |
Not more than 0.30 |
- | - | - |
| 35HML |
0,30- 0,40 |
0,40- 0,90 |
0,20- 0,40 |
0,90- 1,10 |
Not more than 0.30 | 0,20- 0,30 |
- | Not more than 0.30 |
- | - | - |
| 110G13L |
0,90- 1,20 |
11,5- 14,5 |
0,40- 0,90 |
Not more than 0.30 | Not more than 0.30 | - | - | Not more than 0.30 |
- | - | - |
| 110G13KHBRL |
0,90- 1,30 |
11,5- 14,5 |
0,30- 0,90 |
0,80- 1,50 |
Not more than 0.30 | - | - | Not more than 0.30 |
- | 0,002- 0,005 |
0,06- 0,10 |
| Notes: 1. The steel grades 08G2DNFL, 27KHGSNMDTL, 30KHG2STL mass fraction of rare earth metals (yttrium, cerium, etc.) should be in the range of 0,02−0,05%. 2. Permitted deviation in the mass fraction of carbon ±0,02%; in steel, alloyed with additional elements, a deviation in the mass fraction of: manganese, silicon, chromium, Nickel, copper ±0.10 percent of each element; molybdenum +0,05%; titanium -0,005%; vanadium, up +0.02%; niobium -0,02% provided mechanical properties. 3. To improve the wear resistance of castings of steel 110G13L allowed her microalloying with titanium to 0.05 percent, vanadium up to 0.30%, molybdenum up to 0.20%. 4. Numbers and letters in the names of the grades mean: first two digits — the average carbon content in hundredths of a percent, numbers following the letter designation, — average content of the element in per cent; symbol: C — silicon, D — mn, X — chrome, N — Nickel, D — copper, T — Titan, f — vanadium, B is niobium, R is boron, M molybdenum, L — foundry steel. | |||||||||||
Example of designation steel castings, stamps 12KHGFL:
Steel 12KHGFL GOST 21357−87
2. TECHNICAL REQUIREMENTS
2.1. Castings manufactured in accordance with the requirements of this standard, working drawings, regulatory and technical documentation approved in the established order.
Tolerances for the dimensions of castings and machining allowances must comply with GOST 26645, forming slope — GOST 3212.
2.2. Steel for castings, melted in electric furnaces with basic lining. Allowed to produce steel in basic open-hearth furnaces. Mass fraction of sulfur and phosphorus in steel should not be more than 0,020% (of each element).
Note. By agreement with the consumer allowed content of sulfur and phosphorus in all steel up to 0.030% is on each item and in the 110G13L steel grades and 110G13KHBRL phosphorus to 0,080%, provided that the mechanical properties and other requirements of the standard for a period
2.3. Steel casting in the smelting is treated with deoxidizers (modifiers) containing alkaline earth (SSM) and (or) rare-earth (REE), and (or) other metals.
The type and method of processing steel with deoxidants (modifiers), and its amount is set according to the technical documentation of the manufacturer, duly approved.
Technology of melting and deoxidation of cold-resistant steels is given in Annex 2.
2.4. Castings should be heat treated. The type and mode of heat treatment of the casting set according to the technical documentation of the manufacturer, duly approved. The recommended modes of heat treatment of the castings are given in table.2.
Table 2
| Steel grade | The recommended heat treatment regime | Pre- |
Time |
Take |
Take |
Toughness | Solid ness | |
| KCV- 60 |
KCU- 60 | |||||||
| MPa | % | kJ/m |
NV | |||||
| 08G2DNFL | Normalization at 930−970 °C Normalization at 920−950 °C, leave at 590−630 °C |
400 | 500 | 20 | 45 | 2,5 | 4,0 | - |
| 12KHGFL | Normalizing at 930−950 °C |
340 | 470 | 20 | 35 | 2,0 | 3,0 | - |
| 14KH2GMRL | Quenching with 920−930 °C in water, tempering at 630−650 °C |
600 | 700 | 14 | 25 | 3,0 | 5,0 | - |
| 20GL | Normalization at 920−940 °C |
300 | 500 | 20 | 35 | 2,0 | 3,0 | - |
| Quenching with 920−940 °C in water, tempering at 600−620 °C |
400 | 550 | 15 | 30 | 2,0 | 3,0 | - | |
| 20FTL | Normalization at 940−960 °C |
320 | 520 | 20 | 35 | 2,0 | 3,0 | - |
| Quenching with 930−950 °C in water, tempering at 600−650 °C |
450 | 570 | 15 | 30 | 2,0 | 3,0 | - | |
| 20KHGSFL | Normalization at 900−920 °C, leave at 630−650 °C |
320 | 500 | 18 | 30 | 2,0 | 3,0 | - |
| Quenching with 900−920 °C in water, tempering at 650−670 °C |
450 | 600 | 14 | 25 | 2,0 | 3,0 | - | |
| 25KH2NML | Quenching with 860−880 °C in water, tempering at 580−600 °C |
700 | 800 | 12 | 25 | 2,5 | 3,0 | - |
| 27KHN2MFL | Quenching with 880−920 °C in water, tempering at 570−590 °C* |
800 | 1000 | 10 | 22 | 2,0 | 3,0 | 265 |
| 27KHGSNMDTL | Normalization at 910−930 °C, leave at 590−610 °C |
650 | 800 | 12 | 20 | 3,0 | 5,0 | - |
| Quenching from 910−930 °C in water, tempering at 640−660 °C |
700 | 850 | 12 | 25 | 3,5 | 5,0 | - | |
| Quenching from 910−930 °C in water, tempering at 200−220 °C* |
1150 | 1400 | 8 | 12 | 2,5 | 4,0 | 390 | |
| 30GL | Quenching from 920−950 °C in water, tempering at 600−650 °C |
490 | 660 | 10 | 20 | 2,0 | 3,0 | - |
| 30KHG2STL | Normalization at 890−910 °C, leave at 640−660 °C |
600 | 700 | 12 | 40 | 2,0 | 3,5 | - |
| Quenching with 870−890 °C in water, tempering at 640−660 °C |
650 | 750 | 15 | 40 | 2,5 | 3,5 | - | |
| Quenching with 870−890 °C in water, tempering at 200−220 °C* |
1300 | 1600 | 4 | 15 | 2,0 | 3,0 | 400 | |
| 30KHL | Quenching from 920−950 °C in water, tempering at 600−650 °C |
550 | 660 | 10 | 20 | 2,0 | 3,0 | - |
| 35KHMFL | Normalization at 900−920 °C, leave at 640−670 °C |
420 | 630 | 12 | 20 | 1,8 | 2,5 | - |
| Quenching with 890−910 °C in water, tempering at 650−670 °C |
550 | 700 | 12 | 25 | 2,0 | 3,0 | - | |
| 35HML | Quenching with 890−910 °C in oil, leave at 620−640 °C |
600 | 700 | 10 | 18 | 2,0 | 3,0 | - |
| 110G13L | Quenched from 1050−1100 °C in water* |
400 | 800 | 25 | 35 | 7,0 | - | 190 |
| 110G13KHBRL |
Quenched from 1050−1100 °C in water* | 480 | 750 | 20 | 30 | 5,0 | - | 190 |
| ________________ * Used as wear-resistant. Note. Structure steel 110G13L and 110G13KHBRL after the heat treatment must often be austenitic. | ||||||||
2.5. Mechanical properties of steel and the hardness of the casting after final heat treatment shall not be less than specified in table.2.
2.6. Casting must be cleaned of sand, scale and penetration; profit and feeders have been removed. Designated sections of the feeders and profits, bays and burrs shall be ground or chopped within the tolerances according to working drawings.
On the inner surfaces to clean in hard to reach areas of the casting allowed the existence of metal penetration.
Removal of feeders and profits sharp fire should be carried out before the final heat treatment of the castings. For castings of steel 110G13L, 110G13KHBRL and other steel grades specified in sec. 1 of this standard, with wall thickness not more than 40 mm are allowed to cut profits and feeders after final heat treatment.
2.7. The type, number, size and location of defects on the surfaces of the casting that cannot be corrected by welding shall be specified in the working drawings or specifications for specific castings.
2.8. Correction of welding defects of castings, and damaged cast of characters marking is carried out before final heat treatment. Upon detection of defects after final heat treatment and the need for their repair and subsequent heat treatment must be specified in the technical specifications for concrete casting.
2.9. The type, number, size and location-items not admitted internal casting defects (shrinkage and gas cavities, blockage of the axial porosity) should meet the requirements of technical conditions for concrete casting.
3. ACCEPTANCE RULES
3.1. Castings should be subjected to acceptance tests.
3.2. Casting show for acceptance individually or in batches. The party should consist of castings of the same name, made of steel of the same brand, subjected to heat treatment in the same conditions, recorded by automatic devices. The maximum number of casts in the party — technical conditions for concrete casting.
3.3. At acceptance tests should control the appearance and principal dimensions of castings, chemical composition and mechanical properties of steel, the hardness of castings.
3.4. At the request of the customer in the number of controlled parameters additionally include a view of the fracture control of the tides, microstructure, depth bezoperatsionnogo layer, pollution steel non-metallic inclusions, the transition temperature for nil-ductility parameters of resistance to fatigue failure; parameters static, cyclic and dynamic fracture toughness.
Nomenclature and numeric values controlled by additional indicators of the quality of the castings; the volume of sample, number of samples to be tested; the methods and procedures for conducting additional types of control — according to technical conditions for concrete casting.
3.5. Appearance (surface defects of castings — according to claim 2.7) and main dimensions (n.2.1) it is necessary to control each casting.
3.6. The test steel chemical composition (claim 1.1) should be run from each heat. The volume of sample — according to GOST 7565. The results of the monitoring of the chemical composition of the steel extends to the whole casting of this heat.
3.7. Mechanical properties of steel need to be monitored for each heat. Samples for mechanical tests are made from separately molded according to GOST 977 or tidal trial bars. The type and number of test bars — technical conditions for concrete casting. Mechanical properties of steel in tension (claim 2.5) check when testing two samples, the toughness of the steel when tested three samples, if the technical conditions for concrete casting, unless otherwise stated. The test results apply to all castings of this melting, the last heat treatment in the same mode recorded by automatic devices that test bars of this melting.
Note. When flow-mass and large-scale conveyor production of castings control of mechanical properties of steel is carried out according to technical conditions for concrete casting.
3.8. If unsatisfactory test results of at least one indicator of the mechanical properties of steel it is carried out re-test at twice the number of samples, test bars made of the same heat. The results of repeated tests apply to all castings of this melting, the last heat treatment in the same conditions, recorded by automatic devices.
3.9. Test hardness (p.2.5) should be performed for each casting. When flow-mass and large-scale conveyor production of castings allowed selective control of hardness. Sample size: for the technical conditions for concrete casting. The results of sampling apply to all castings submitted for lot acceptance.
When unsatisfactory results of testing of hardness for at least one casting of the sample carried out continuous control.
4. TEST METHODS
4.1. Appearance (surface defects of castings — p. 2.7) should be monitored visually without the use of magnifying means by capillary or magnetic flaw detection or other methods according to the technical specifications and the technical documentation for concrete casting and methods of control.
4.2. The principal dimensions of the casting (p.2.1) check universal measuring instruments.
4.3. Samples for determining the chemical composition of the steel should be selected in accordance with the requirements of GOST 7565. Allowed to check the chemical composition of the chips taken from the test bars for mechanical testing or from the cast.
4.4. The chemical composition of the steel (p.1.1) should be determined according to GOST 22536.0 to GOST 22536.5;GOST 22536.7 — 22536.12 GOST; GOST 12344 — 12348 GOST; GOST 12350 — 12352 GOST; GOST 12354 series — 12357 GOST; GOST 12360, 12361 GOST, GOST 27809.
Allowed to use certified in the prescribed manner, other methods of determination of chemical composition of elements, the accuracy of which is not below the accuracy of the respective methods on these standards.
4.5. The configuration and size of separately cast test bars for determining the mechanical properties of steel according to GOST 977. The size and location of tidal test bars — on drawings of castings.
Separately cast test bars or cut from them of the workpiece to determine the mechanical properties of steel subjected to heat treatment under the same regime as the casting of this heat. Tidal test bars before carrying out the heat treatment are cut, and after final heat treatment are separated from the casting and mark. Allowed to determine mechanical properties on specimens cut from castings.
Note. With the release of metal from the smelting furnace two bucket metal bucket each be considered a separate fuse.
4.6. Mechanical properties of steel in tension (claim 2.5) determined according to GOST 1497 on samples of 10 mm diameter and the estimated length of 50 mm.
When cutting samples from the castings and re-tests allowed to determine the mechanical properties of steel samples with a diameter of 5 mm and an estimated length of 25 mm.
As indicators of mechanical properties of steel in tension taking the arithmetic means of the test results.
4.7. The impact strength of steel (n.2.5) should be determined according to GOST 9454 on samples of types I and II. As toughness take the minimum values of test results of samples of each type.
Notes:
1. When providing requirements to impact toughness KCVimpact strength KCU
not determine.
2. Requirements to impact toughness KCVare optional
4.8. Hardness of castings Brinell (p.2.5) should be determined according to GOST 9012. Locations of hardness testing — according to the drawings of castings.
4.9. The inconsistent casting (p.2.9) should be determined by x-ray or gamma radiography, or other methods of control according to the technical specifications and the technical documentation for concrete casting and methods of control.
5. MARKING, PACKAGING, TRANSPORTATION AND STORAGE
5.1. Each casting shall be cast, embossed or marked with indelible paint marks marking:
distinctive number or mark of the manufacturer;
the last two digits of the year of manufacture;
serial number of castings according to the numbering system of the manufacturer;
the designation of the steel grade;
acceptance stamp of technical control of the manufacturer.
5.2. The placement and size of signs marking — the drawing of the casting. In case of impossibility of placing on the cast of characters marking the casting should have a tag with the marking and stamp of the technical control showing the number of casts in the party. When flow-mass and large-scale conveyor production marking of castings is carried out according to technical conditions for concrete casting.
5.3. Every batch of casting is accompanied by the document certifying their compliance with the requirements of this standard and containing:
the name of the manufacturer and location (city or conditional address);
the name of the casting and drawing number;
the number of castings in the batch;
rooms melting and casting according to the numbering system of the manufacturer;
designation (designation) of the steel grade;
the designation of this standard;
the final results of chemical analysis and mechanical tests from smelting (melting).
5.4. The castings are Packed in accordance with the requirements of technical conditions for concrete casting.
5.5. Casting transporterowych railway, water, automobile and air transport in accordance with cargo carriage regulations applicable to transport of this species.
5.6. Storage conditions of castings in the impact of climatic factors should correspond to the group ОЖ4 GOST 15150 in the absence of a corrosive environment. Allowed to keep casting outdoors.
6. MANUFACTURER’S WARRANTY
6.1. The manufacturer guarantees the conformity of the castings to the requirements of this standard subject to the rules of operation, transportation and storage.
6.2. The warranty period is set out in technical conditions for concrete casting.
ANNEX 1 (recommended). APPOINTMENT GRADES OF STEEL FOR COLD-RESISTANT CASTINGS
ANNEX 1
Recommended
| Steel grade | Appointment |
| 08G2DNFL | Large hull casting; the upper part of the frames of the crankcases, bearings, castings excavators heavy-duty and other carepayment details high tensile strength |
| 12KHGFL | Responsible castings of tractors, welded cast bearing structures |
| 20 HL, 20FTL | Responsible cast parts of automatic coupler and bogies |
| 14KH2GMRL, 20KHGSFL, 25KH2NML | Responsible welded-cast structures of large sections of career and draglines |
| 35KHMFL, 35HML | Responsible castings of the mining equipment |
| 27KHN2MFL | Solid the teeth and their fastening elements (staples, wedges) ekskavatorov |
| 27KHGSNMDTL | Tips rippers frozen soil rollers heavy bulldozers, wheel drive gear, sprocket, caterpillar machines etc. |
| 30GL, 30KHL | Housing of shock-absorbing units of freight wagons |
| 30KHG2STL | Shoes caterpillar machines, angle bulldozer blades, cremallera gear excavators, rollers dredge chains, working bodies of mining machines, levers, gears |
| 110G13L, 110G13KHBRL | Teeth of excavator buckets, crawler links, the working parts of the crushing equipment |
APPENDIX 2 (recommended). TECHNOLOGY OF MELTING AND DEOXIDATION OF STEEL COLD-RESISTANT
ANNEX 2
Recommended
The application specifies the features of the technology of melting and final deoxidation of cold-resistant steel with guaranteed impact toughness at minus 60 °C required by this standard.
Steel smelted in electric-arc furnaces with a basic lining dvuhklikovy process with the use of standard ferroalloys.
Basicity of slag in the period of melting in electric arc furnaces should be within 2.5 and 3.0. By the release of the basicity of the slag should not be less than 2.5 and the content of oxide — not more than 0,6−0,8%. Basicity of slag is achieved by using svezheokrashennoj lime; it is allowed to replace it with limestone from the calculation of 1.4 tons per 1 ton of lime.
During the period of oxidation must be oxidized at least 0.3% carbon to obtain a carbon content at the lower limit, or 0.05 percent, below the lower limit in the specified grade of steel.
In case of insufficient removal of phosphorus and high content of chromium (in steel, not chrome elegiremos) needs to be repeated descent (the downloading of slag).
In the process of electric arc smelting pre-deoxidation of metal is carried out in the beginning of the recovery period after maximum removal of oxidative slag additive lump of aluminium (0,03−0,05%). Alloying additives (Nickel, copper, ferrosilicon, ferromolybdenum, ferromanganese, ferrochrome) is introduced based on the average fine the contents without taking into account the frenzy, and then give a slag forming in the amount of 2.5−3.5% of the mass of the melt.
Bulk aluminum for final deoxidation from the calculation 0,20% of the mass of the melt (for steel with carbon content up to 0.30%) and 0.15% (for steel with a carbon content of more than 0.30%) it is recommended to introduce into the oven on the rod for 1−2 min until the release.
The metal from the electric arc furnace produced in the bucket with the slag.
When filling the bucket approximately to the height under the seat of the ligature with alkaline earth metals (SSM) introduction 0,025−0,035% calcium, and then enter ferrotitanium in the upper limit of the fine to its content in the steel without regard to fervor, ferrovanadium and ferroniobium is based on the average content in the specified steel grade.
When deoxidation (modification) steel titanium number of input pieces of aluminium should be adjusted downward.
Mass fraction of aluminium in all grades of steel is recommended in the range of 0,03−0,06%. For steel grades 27KHGSNMDTL, 30KHG2STL recommended a partial (or full) replacement of aluminum by titanium is based the total content of aluminum and titanium in the range of 0,03−0,06%.
To increase the level and stabilization of the fracture toughness at minus 60 °C, it is recommended to modify the steel alloys of rare earth metals. Alloys of rare earth metals (0.05% of rare earth metals in the calculation) is introduced into the bucket on the rod after filling. It is recommended to introduce the ligature SSM and REM the injection of powdered materials in a stream of argon.
Casting is recommended using a Cup with a diameter of not less than 50 mm.
The electronic text of the document
prepared by JSC «Code» and checked by:
Casting of metals and alloys: a Collection of standards.
M.: IPK Publishing house of standards, 2002
