1. Is the annealing temperature reached the specified level? Stainless steel heat treatment typically involves solid solution heat treatment, commonly known as "annealing," with a temperature range of 1120℃ (Japanese standard). You can also observe through the observation port of the annealing furnace; the stainless steel tube in the annealing zone should be in a bright, incandescent state, but without any softening or sagging.

2. Annealing Atmosphere. Pure hydrogen is generally used as the annealing atmosphere, with a purity of 99.99% or higher. If the other part of the atmosphere is an inert gas, the purity can be slightly lower, but it cannot contain excessive oxygen or moisture.

3. Furnace Sealing. The bright annealing furnace should be sealed, isolated from external air; for those using hydrogen as the protective gas, only one exhaust port is open (used to ignite the expelled hydrogen). The inspection method involves applying soap water to the joints and gaps of the annealing furnace to check for leaks; the most prone to leakage areas are where the pipes enter and exit the furnace, as the sealing rings in these areas are particularly susceptible to wear, and they should be inspected and replaced regularly.

4. Protecting gas pressure. To prevent micro-leaks, the protective gas within the furnace should maintain a certain positive pressure; for hydrogen protective gas, it is generally required to be above 20kBar.

5. Kiln Internal Steam. Firstly, check if the kiln material is dry; for the initial loading, the kiln material must be dried thoroughly. Secondly, ensure that there is no excessive water residue on the stainless steel pipes entering the kiln, especially if there are holes in the pipes. Otherwise, water leakage can ruin the kiln atmosphere.