SAE AMS 2770R:2020 pdf free

SAE AMS 2770R:2020 pdf free.Heat Treatment of Wrought Aluminum Alloy Parts
Shall be air, molten salt bath, oil bath, or fluidized bed. The products of combustion and other materials that could contaminate parts shall not come into contact with parts during solution heat treating, annealing or stress relieving. Electrical heating elements and radiant tubes shall be shielded to prevent parts from being exposed to direct radiation. Shield construction and placement shall be such as to prevent parts from being exposed to re-radiation of heat from electrical elements or radiant tubes. Composition and maintenance of salt baths and fluidized beds shall be such as to prevent attack of the parts.
During solution heat treatment, soaking shall be performed without interruption. During aging, annealing, stress relieving,and heat treatment to the 01 (formerly T411) temper, a maximum of four interruptions, with doors open for not more than 2 minutes during each, is permissible for removal or loading of parts. Door opening durations greater than 2 minutes are permitted provided the time between the door opening and recovery of furnace temperature is not included in the total time.
Entrapped water shall be prevented from entering the furnace. The loading of parts directly from a water-containing quench tank (i.e., wet parts) into a furnace is prohibited. Ammonium fluoborate, or equivalent, should be used in air furnaces as necessary; however, purging the furnace with fresh air may be necessary to prevent discoloration of subsequent loads of parts made from Alclad product. Parts with blisters, as a result of hydrogen induced porosity, shall be rejected.
For solution heat treating of parts made from Alclad product under 0.125 inch (3.18 mm) thick, the furnace recovery time shall not exceed 30 minutes, and for parts made from heavier Alclad product, shall not exceed 60 minutes.
Parts made from product over 0. 125 inch (3. 18 mm) in nominal thickness shall be limited to two solution heat treatments in addition to any by the material producer. Parts made from product 0.020 to 0.125 inch (0.51 to 3.18 mm) in nominal thickness, shall be limited to one additional solution heat treatment in addition to any by the raw material producer. For parts made from product under 0.020 inch (0.51 mm) in nominal thickness, additional solution heat treatments are prohibited.SAE AMS 2770R pdf free download.