Rods are made of 20Cr23Ni18 (EI417), CrNi77TiAlB (EI437Б), CrNi77ТTiAlBU-PA (EI437BU-PA), CrNi67MoWTiAl-VA (EP202), CrNi65WMoTiAl(EI893), CrNi70WMoTiAl(EI617), CrNi70WMoTiAlNb-VI(EI598-VI), CrNi38WTi (EI703), CrNi35WTi (EI612) and other nickel heatproof alloys.
The grade contains the production method after “-” symbol: PA - plasma melting with further vacuum-arc remelting; VA - vacuum-arc remelting; VI - vacuum-induction melting.
The chemical material of the above-mentioned materials is given in GOST 23705-79 standard.
Production
Heatproof rods can be round or square and are made by hot rolling or forging. These semi-finished products are supplied without thermal processing. The product surface is mechanically processed (chipped).
The sizes, mechanical properties, supply condition of these products are regulated by GOST 23705-79 standard.
Round rods are often called “heatproof round bars”. This is correct for semi-finished products of a large diameter. E.g., heatproof round bars of Ø 50 mm, 60 mm, 80 mm and higher. GOST 25501-82 does not contain the definition “round bar” for blanks and semi-finished products, but in fact, round rods of large diameter are often called so.
Application
Heatproof rods are widely used in industries with strict requirements towards the mechanical strength of products working under high temperatures. Such industries include power-plant industry so as aircraft and rocket engineering. Applications of rods made of heatproof alloys include the production of fastening components and welded articles of gas turbines.