Heat treatment can be divided into stress relief annealing, intermediate annealing and pre oxidation treatment.
(1) Stress relief annealing: 430-540 ℃, holding time 1-2h, furnace cooling or air cooling.
(2) Intermediate annealing is to eliminate the work hardening phenomenon caused by cold rolling, cold drawing and cold stamping, so as to facilitate the continuous processing. The workpiece should be heated to 700-800 ℃ in vacuum or protective atmosphere, and kept for 30-60min, then cooled in furnace, air or water.
(3) Preoxidation: when the combined gold is used as sealing material, it should be pre oxidized before sealing. A uniform and dense oxide film is formed on the surface of the alloy. The parts are heated in saturated wet hydrogen at 1100 ℃ for 30 min, and then oxidized in air at about 800 ℃ for 5-10 min. The appropriate weight gain of parts is 0.1-0.3mg/cm2 .The alloy cannot be hardened by heat treatment.
Surface treatment process of 4j52
Before heat treatment, welding or glass sealing, the dirt and grease on the metal surface must be removed. When the oxide layer is serious, sandblasting or soaking in molten alkali solution before pickling can be used. Slight scale can be pickled with 25% hydrochloric acid solution at 70 ℃.
Cutting and grinding performance of 4j52
The cutting characteristics of the alloy are similar to that of austenitic stainless steel. High speed steel or cemented carbide tool is used in machining, and coolant can be used when cutting at low speed. The grinding performance is good.