In the production of large flanges, there are many factors that affect the performance of large flanges. Here are some common factors, First, annealing temperature (The annealing temperature is the temperature parameter when the primer and template are combined. When 50% of the primer and complementary sequence are double-stranded DNA molecules, the temperature is an important factor that affects the specificity of PCR. In an ideal state, the annealing temperature is low enough to ensure the effective annealing of the primer and the target sequence, and also high enough to reduce the non-specific binding. The reasonable annealing temperature is from 55 ℃ to 70 ℃. The annealing temperature is generally set to Tm of primer should be lower than 5 ℃) whether the annealing temperature reaches the required temperature. Large flange is generally treated by solution heat treatment, which is commonly known as “annealing”, and the temperature range is 1040~1120 ℃ (Japanese standard). You can also observe through the observation hole of the annealing furnace. The large flange pipe fittings in the annealing area should be incandescent, but there is no softening and sagging.
The second is the pressure of protective gas. In order to prevent slight leakage, the protective gas in the furnace should maintain a certain positive pressure. If it is hydrogen protective gas, it is generally required to be above 20kBar. Annealing atmosphere: generally, pure hydrogen is used as the annealing atmosphere, and the purity of the atmosphere is more than 99.99%. If the other part of the atmosphere is inert gas, the purity can also be lower, but it must not contain too much oxygen and water vapor.
The second is the sealing of the furnace body (the shell is welded with steel plate and section steel, the trolley is welded with section steel and steel plate, the trolley reduces the loss of heat radiation and convection through soft contact with the furnace lining and sand sealing mechanism, effectively ensuring the sealing of the furnace body.), the bright annealing furnace should be closed and isolated from the outside air; If hydrogen is used as protective gas, only one exhaust port is open (used to ignite the discharged hydrogen). The inspection method can be used to wipe the joints of the annealing furnace with soapy water to see if there is gas leakage; Among them, the place where gas is easy to escape is the place where the annealing furnace enters the pipe and exits the pipe. The sealing ring in this place is particularly easy to wear, and it needs to be inspected and replaced frequently.