These specifications apply to delivery hot rolled thick sheets hot-rolled sheet steel (rev. 2) (rev. 3) made of heat-resistant and heat-resistant alloys of grades XN78T (EI 435), KhN78T-VD (EI 435-VD), KhN60VT (EI 868), KhN75MBTYu (EI 602).
1.1. (2) Hot rolled sheet steel hot-rolled sheet metal (rev. 2) (rev. 3) is manufactured in the following dimensions, mm:
|3−3.5||1000||2000 (rev. 3)|
1.2. (1) Limit deviations in dimensions must comply with GOST 19903−74 (normal accuracy).
1.3. Sheets that have not been cut by cutting are shipped with actual dimensions in an amount of not more than 20% of the batch.
1.4. Sheets with a thickness of more than 11 mm are supplied by agreement between the manufacturer and the consumer.
1.5. (3) The flatness of the sheets should be no more than 15 mm per meter of length.
An example of a symbol.
Alloy grade ХН75МБТЮ, M3b 1b (rev. 1) surface group, size 6x1000x2000 mm.
Sheet 6x1000x2000-KhN75MBTYu-M3b-TU 14−1- 4296−87
2. TECHNICAL REQUIREMENTS
2.1. The chemical composition of the alloys must comply with GOST 56−32−72.
2.1.1. The calcium content in the alloy KhN60VT (EI 868) should not exceed 0.05%. Calcium is introduced into the alloy KhN60VT (EI 868) by calculation and is not determined by chemical analysis.
2.2. Sheets are delivered in a heat-treated state, straightened, with cut edges and an etched surface.
2.3. Mechanical properties determined on samples cut from sheets in the state of delivery and recommended heat treatment modes should correspond to table. 1.
|Alloy grade||Recommended heat treatment mode||Test temperature ° С||Mechanical properties|
|Temporary resistance break (meas. 3) N / mm 2 (kgf / mm 2)||Elongation, not less, 5|
|Hardening from 980−1020 ° C in water, in air or under a water shower.||20
|n.b. 880 (90)
n.m. 180 (18)
|KhN75MBTYu (EI 602)||Hardening from 1050−1080 ° C in water, in air or under a water shower.||20
|n.b. 930 (95)
n.m. 250 (25)
|KhN60VT (EI 868)||Hardening from 1150−1200 ° C in water, in air or under a water shower.||20
|n.b. 980 (100)
n.m. 200 (20)
Note: If unsatisfactory values of the mechanical properties of sheets are obtained for any indicator, it is allowed to re-heat treatment and test as from a newly submitted batch. In this case, the grain size for the KhN60VT alloy (EI 868) can be no larger than 4 points.
2.4. The sheets as delivered are checked for the actual grain size. The grain size should not be larger than 5 points in accordance with GOST 5639−82.
2.5. Other technical requirements for sheets, incl. in terms of macrostructure, surface quality must comply with GOST 24982-gr. 1b with the following additions: after etching, sheets can have a matte surface with gray tints.
3. RULES OF ACCEPTANCE AND TEST METHODS
3.1. Sheets are handed over in batches. The batch must consist of sheets of the same heat, the same thickness and the same condition as delivered.
3.2. To determine the mechanical properties, two samples are taken from a batch for each type of test.
3.3. Tests of fur properties at elevated temperatures are carried out in accordance with GOST 9651−84.
3.4. Sheets with a thickness of 6.0 mm and more are allowed to be tested on round specimens.
3.5. All other requirements regarding acceptance rules and test methods according to GOST 24982−81 and GOST 7566−81.
4. MARKING, PACKAGING, TRANSPORTATION, STORAGE AND REGISTRATION OF DOCUMENTATION.
4.1. Marking, packaging, transportation, storage and paperwork must comply with GOST 24982−81.
Note: Prices for products are approved by the USSR State Committee for Prices and are published in price lists. (rev. 1).
Registered TsNIICHM: 220787
/ Head Department of Standardization of Ferrous Metallurgy
V. T. Ababkov.