| 摘要 |
<p>Heat treatment process for rolled metallic products avoids the formation of harmful vapours inside the furnace from the oil present on the product surface. The products are heat treated in a controlled furnace atmos. of pressure less than 1 bar which is kept constant by a liquid ring pump with a pressure control device and an intermediate buffer chamber. When the temp. has reached 200 to 300 degrees C, the pumping is stopped and the treatment continued at an atmospheric pressure above that used in the first stage. The atmos. is stirred by a fan.</p> |
