SU505746A1 - The method of chemical heat treatment - Google Patents

Description

(54) METHOD OF CHEMICAL-THERMAL TREATMENT

Table 1

 Similar to the known method.

Example. Sheets with a thickness of 0.8-1.2 mm from hardened alloys of grades SB1 (composition, wt.%: Zr 1.1; Ta 0.2; the rest is niobium) and 5BMC (composition, wt.%: W 5.3 ; Mo 2.0; Zr 1.1, the rest is niobium). The oxygenation under the carburizer layer is carried out in air at 800 ° C for 6 hours, the leveling annealing is carried out in a vacuum of 5-10 mm. Hg Art. at 1100 ° C for I hour, annealing for stress relief — in a vacuum of 5 10 Torr at 1250 ° C for 4 hours.

From: Changes in the composition and strength of alloys based on niobium SB1 and 5VMC after annealing at 1250 ° C for 4 hours are shown in Table. 2

Yield point, kgf / mm

34

Chemical-thermal treatment according to the proposed method makes it possible to harden the alloys to a greater extent than by a known method. The material retains sufficient ductility (at 20 ° C, the elongation is 8-12%). The processing is carried out on widespread equipment and does not cause difficulties in forging, rolling, stamping or welding, since these operations can be performed on pre-strengthened metals.

Claims (3)

1. A method of chemical-thermal treatment of refractory metals, including internal oxidation at a temperature below the recrystallization temperature, followed by annealing, characterized in that, in order to increase the strength, before oxidation, the metal is hardened. 2. The method according to claim 1, wherein the internal oxidation is carried out at a temperature of 200-300 ° C below the recrystallization temperature. 3. The method according to claim 1, characterized in that the annealing is carried out in two stages: at 900-1200 ° C and 1200-1300 ° C.