bal6-1.5. Aluminum cupronickel is a structural copper-nickel alloy, which can be strengthened by heat treatment, and has high strength and good elasticity. The tensile strength meets the requirements of BAL6-15. Aluminum white copper strip, inspection, warehousing. Strip that does not meet the requirements is based on the difference between the tensile strength of the strip after the first annealing and the required tensile strength, according to BAL6-15. Aluminum cupronickel returns to the annealing working curve again, and the second and third return annealing are carried out until the qualified product is produced. 
Standard: GB T 2051-1989 Chemical Composition: BAL6-15. Aluminum, cupronickel, copper, Cu: Margin, nickel + cobalt, Ni + Co: 55～6.5Pb: 0003 Aluminum al: 12～1.8 iron Fe: 050 manganese mn: 020 Notes: 11 (impurities).
And for the backlog of 40 furnace strips with unqualified mechanical properties, the above method is used to re-annealing again. In the production of BAL6-1 with tensile strength that meets the requirements5. At the same time, with a large amount of data, constantly correct and improve BAL6-15. Aluminum-white copper returns to the annealing working curve again. The annealing temperature, holding time and tensile strength of the strip are shown in Table 5. After adopting the new process and controlling the processing rate of the finished product by 35% to 47%, the return annealing is carried out. The annealing temperature is 300 for 2h, and after annealing, the tensile strength does not meet the requirements of BAL6-15. Aluminium cupronickel strip according to BAL6-15. Aluminum cupronickel returns to the annealing working curve again, and returns to annealing again. The results show that the curve can meet the production needs. Mechanical properties: tensile strength b (MPa): 539 elongation δ10 (%3 Note: The tensile mechanical properties of the plate are between 410 450, with the increase of annealing temperature, the tensile strength decreases, and with the increase of annealing temperature, the tensile strength decreases, showing a continuous and uniform linear change. Heat treatment specification: casting temperature 1200 1250 quenching temperature 900 tempering temperature 500 hot working temperature 850 900 . 
After re-annealing, bal6-15. The tensile strength of aluminum white copper strip remains unchanged or basically unchanged. Again the annealing temperature is between 410 423 or 438 450, and after annealing, BAL6-15. The tensile strength of aluminum white copper strip increases. Again return to annealing at a fixed temperature between 423 430 or 430 438, after annealing, BAL6-15. The tensile strength of aluminum white copper strip decreases.