METHOD OF THERMO-MECHANICAL TREATMENT OF HEAT-RESISTANT ALLOY CONTAINING TUNGSTEN FOR ENHANCEMENT OF CREEP RESISTANCE AND HEAT-RESISTANT ALLOY THE SAME

摘要

The present invention relates to a method of a thermomechanical treatment of a heat-resistant alloy containing tungsten to enhance creep resistance, and alloy manufactured thereof. The thermomechanical treatment method wherein a heat-resistant alloy is thermally treated and then processed comprises: a step of performing a solution treatment on the alloy at a temperature of 1260-1280C for a predetermined time; a step of performing slow cooling at a cooling rate of 5-10 C/min until a temperature is reached between 1100-1150C to immediately perform an aging treatment; a step of performing the aging treatment at a temperature of 1100-1150C for a predetermined time; and a step of performing air-cooling, thus grain boundaries in the heat-resistant alloy becoming serrated while carbide in a lamella form possibly formed on the grain boundaries is inhibited due to the temperature range of the aging treatment. Basic properties of nickel-based alloys are maintained while the grain boundaries in the heat-resistant alloy become serrated to induce precipitation of stable carbide with low interfacial energy; enhances an adhesive force between the grain boundaries and the base; and introduces dislocation inside the grain boundaries by a subsequent mechanical processing method after performing a cold processing process with a processing quantity in a range of 5-10%. As such, the method has the effects of inhibiting concentration of damage to the grain boundaries by precipitation of fine carbide at the grain boundaries while in use to improve resistance to creep, fatigue, oxidation, corrosion, and other intergranular cracking damages.