TU 14-1-850-74 extract
Extract
These technical conditions apply to hot-rolled and forged rods and bars of press products made of iron-nickel-based alloy grade 08ХН35ВТЮ-ВД (ЭИ787-ВД).
1.1 Rods are manufactured:
Round - diameter from 8 to 180 mm
1.2 In terms of shape, dimensions and tolerances, hot-rolled and forged rods must comply with the requirements of GOST 22411-77, while hot-rolled round rods must comply with the 2nd and 3rd accuracy groups. The accuracy group is specified in the order. If the accuracy group of the rolled products is not specified in the order, the rolling of round rods is carried out according to the 3rd accuracy group.
2 Technical requirements
2.1 The chemical composition of the alloy grade 08KhN35VTYu-VD (EI787-VD) must comply with the requirements of Table 1.
| Mass fraction of elements, % | ||||||||||
| carbon | silicon | manganese | sulfur | phosphorus | pine forest | tungsten | chromium | nickel | titanium | aluminum |
| No more | 2.8-3.5 | 14.0-16.0 | 33.0-37.0 | 2.6-3.2 | 0.70-1.40 | |||||
| 0.08 | 0.6 | 0.6 | 0,010 | 0,020 | 0.02 | |||||
2.3 The mechanical properties of rods at room temperature and long-term strength are tested on samples cut from heat-treated blanks using one of the modes given in Table 2. The mechanical properties and long-term strength must comply with the requirements of Tables 3 and 4.
Table 2
| Heat treatment |
Option 1 Hardening from temperature (1140 + 20 -10 )°C, holding for 4-8 hours, air cooling. Quenching from a temperature of (1050 ± 10)°C, holding for 4 hours, air cooling. Aging at a temperature of (750-790)°C for 16-25 hours, air cooling. |
Option 2 Hardening from temperature (1080 -1120)°C, holding for 10 hours, air cooling. Aging at a temperature of (750-800)°C for 16-25 hours, air cooling |
Table 3
Option heat treatment |
Mechanical properties, not less than | |||||||
Ultimate strength, σ in N/ mm2 (kgf/ mm2 ) |
Limit yield strength, σ 0.2 N/mm 2 (kgf/mm 2 ) |
Relative elongation, δ 5 , % |
Relative narrowing, ψ, % |
Impact viscosity KCU J/ cm2 (kgf m/cm 2 ) |
Brinell hardness (diameter print), mm | |||
1 2 |
980 (100) |
635 (65) |
8 | 10 | 29 (3) |
3.25-3.60 | ||
Table 4
Option heat treatment |
Test temperature, °C | Constantly attached stress, N/ mm2 (kgf/ mm2 ) |
Time until destruction per hour, not less than |
| 1 | 550 | 720 (73) | 80 |
| 1 | 750 | 290 (30) | 100 |
| 2 | 550 | 720 (73) | 80 |
| Note - the heat treatment option and test mode for heat treatment option 1 are specified in the order. If the heat treatment option and test mode are not specified, the supplier is allowed to use any heat treatment option and test mode. | |||
2.4 The macrostructure of the rods must be free of voids, holes, cracks, delaminations and coarse pores and slag inclusions visible to the naked eye.
The grain size variation is checked on rods with a diameter from 20 to 55 mm inclusive on 2 longitudinal sections heat-treated according to the mode of Table 2.
Hot-rolled rods with a diameter of 20-55 mm are checked for the presence of general banded heterogeneity, which should not exceed 2 points on scale No. 3 of GOST 22838-77.
The test is carried out on two longitudinal samples, heat-treated according to the conditions in Table 2.
2.5 Round bars with a diameter of 80 mm or more are subject to ultrasonic testing.
Round bars are checked by two longitudinal chamfers located in mutually perpendicular planes.
100% of rods are subjected to ultrasonic testing.
2.6 There should be no cracks, folds, or films on the surface of the rods. The above defects should be removed by gentle grinding. The depth of grinding of defects should not exceed the maximum deviation in size, calculated from the nominal value.
Small hairlines, scratches, dents, and ripples within the one-sided tolerance are allowed without cleaning.
The ratio of the depth of the cut to its width should be at least 1:6.
3.7.2 The quality document must be signed by the quality control department of the supplier plant and the technical acceptance representative of RT-Tekhpriemka JSC or another authorized organization.
