Alloy ВТ18У

Designation

Name	The value
Designation GOST Cyrillic	ВТ18У
Designation GOST Latin	BT18U
Transliteration	VT18U
By chemical elements	ВTe18У

Description

Alloy ВТ18У used: for the production of bars, rods, forgings and stampings, sheet metal; parts of gas turbine engines operating in the temperature range of +550−600 °C.

Note

Pseudo α-alloy ВТ18У different from ВТ18 lower content of aluminum and zirconium, and the additional alloying with tin. In this regard, he is somewhat smarter ВТ18. At the high-temperature properties of the alloy ВТ18У is not inferior to the alloy ВТ18 and is recommended for the same operating conditions as the alloy ВТ18.

Standards

Name	Code	Standards
Bars	В55	OST 1 90006-86, TU 1-92-51-77
Non-ferrous metals, including rare, and their alloys	В51	OST 1 90013-81, OST 1 90197-89, OST 1 90002-86

Chemical composition

Standard	C	Si	Fe	N	Al	Ti	Mo	Sn	Nb	O	Zr	H
OST 1 90013-81	≤0.1	0.1-0.25	≤0.2	≤0.04	6.2-7.3	Rest	0.4-1	2-3	0.5-1.5	≤0.14	3.5-4.5	≤0.015

Ti is the basis.
According to OST 1 90013-81 the total content of other impurities is ≤ 0.30%. A partial replacement of molybdenum by tungsten in an amount not exceeding 0.30% is allowed. The total content of molybdenum and tungsten should not exceed the norms specified in the table for molybdenum. The total content of copper and nickel in an amount not exceeding 0.10% is allowed, including nickel not more than 0.080%. The total content of chromium and manganese in an amount not exceeding 0.15% is allowed.

Mechanical properties

Section, mm	σ_U, MPa	d₅, %	y, %	KCU, kJ/m²	HB, MPa	HRC
The blades of aircraft engines is made by forging after annealing (microgravity (Mg) is the projected area up to 20 cm2, small (M) - 20-250 cm2)
Мг, М	930-1130	≥10	≥27	≥245	255-341	28-38.5
Forged discs and shafts after heat treatment OST 1 90197-89 all weight categories
-	≥560	-	-	-	-	-
The blades of aircraft engines is made by forging with the use of thermo-mechanical processing and forging in isothermal conditions, including the conditions of superplasticity after aging (microgravity (Mg) is the projected area up to 20 cm2, small (M) - 20-250 cm2)
Мг, М	930-1130	≥10	≥25	≥245	255-341	28-38.5
Forged discs and shafts after heat treatment OST 1 90197-89 (samples cut in Cordova direction; specified blank weight categories)
≤50	910-1110	≥7	≥15	≥225	-	-
50-100	980-1080	≥6	≥14	≥225	-	-

Description mechanical marks

Name	Description
σ_U	Limit short-term strength
d₅	Elongation after rupture
y	The relative narrowing
KCU	Toughness
HB	Brinell hardness number
HRC	Rockwell hardness (indenter diamond spheroconical)