Relevance

Pipe KHN78T of corrosion-resistant special steels belong to the category of heat-resistant. Intended for the production of parts that operate at high temperature (1000 — 1100ºС) in aggressive environments. Due to the high content of Nickel and chromium, the tube made of this alloy have high corrosion resistance, providing increased reliability of the equipment. Nickel on the surface oxide forms a solid film whose presence is consistent GOST 14162−79. However, this alloy is not stable enough in the atmosphere of sulfur compounds and sulfur. Because of the content in the composition of the alloy of chromium, Nickel and titanium tubes are more expensive but are more reliable. Their cost kompensiruet durability and strength of the material.

Manufacture of pipe

Of the tubes extremely thin-walled Ø 5−250 mm and a wall thickness of 0,3−6 mm. thin-walled Tubes have Ø 5−250 mm with a thickness of 0,6−20 mm. Thick-walled pipes — Ø 6 to 250 mm with a thickness of 1,6 — 24 mm. Especially thick-walled pipes — Ø 6 to 70 mm, wall thickness from 2 to 12 mm. High ductility of the alloy allows the capillary tube. With an outer diameter of 0.3−120 mm and wall thickness of 0.08−5 mm, such tubes are measured (from 4 to 7m), random (0.3 to 7m), multiple lengths of over 4 meters Can be supplied in coils (not more than 160 m). The ends of the tubes at a diameter of 1.6 mm are processed and cropped. With a smaller diameter (up to 1.6 mm the ends trimmed). The tube must be subjected to cleaning with a jet of air with a pressure of 0.49 MPa.

Deviations

If the internal pipe diameter > 0.6 mm limit deviations of the diameter may not exceed deviations in the outer diameter more than 0.01 mm. the Production of capillary tube provides for a combined maximum deviations, i.e. or the external diameter with precision or wall thickness ordinary precision. The curvature of tubes shall not exceed 3 mm for a distance of 1 m. the surface must be smooth, clean, without deformation, marks, dents, etc.

Mechanical properties KHN78T at a temperature of 20°C

— The ultimate short-term strength from 590 MPa to 880 (depending on pipe diameter) decreases with increasing temperature;

— when the rupture elongation is not more than 40%;

— for permanent deformation, the yield strength changes. The minimum rate — at 800 °C is 98 MPa, and further heating it increases to 105 MPa at 1100 °C.

Physical properties KHN78T alloy at t° =100°C

— temperature coefficient or linear expansion is 12.2 [1/Deg];

— modulus of elasticity equal of 2.19 MPa;

— coefficient of thermal conductivity or the heat capacity of the alloy is not more than 14.6 W/(m·deg);

— the density of the alloy is of 8.38 g/cm3, and when the temperature changes moderately;

the resistivity is equal to 1.1 Omhm²/m.

Application

Pipe KHN78T used in almost all industrial sectors, so it is the most popular of all types of hire. Such a pipe are indispensable in engineering, aviation, gas and oil industry, and power industry. These tubes are designed for operation at temperatures not exceeding 1100 °C. alloy KHN78T is made of a capillary tube, which is a thin-walled pipes of small sizes, which feature high strength and low weight. Such pipe typically attached to a round, and sometimes of the profile cross-section: square, oval and rectangular.

Buy at best price

In stock company «AVEK global» — the widest offer of pipes of steel grade KHN78T on the most favorable terms. Price due to the technological features of production without the inclusion of additional costs. All the pipe batches have the quality certificate on conformity to requirements of standards and technical conditions. The certificate is marked manufacturer, brand alloy mechanical properties of the pipes, the chemical composition and the results of additional tests, such as pressure testing, or testing. Implementation of orders in the shortest possible time. Wholesale buyers are offered preferential discounts.