Controlled atmosphere furnace

Controlled atmosphere furnaces have now largely superseded box (pack carburising) and salt bath furnaces on the basis that they exhibit better furnace control, more efficient throughput and are less labour demanding.

They also offer much improved environmental conditions of operation, without the serious problems of land contamination with toxic salts (cyanides) and the difficulties of disposing of waste salts, contaminated jigs and fixtures and pack carburising waste.

Controlled atmosphere furnaces fall into two major categories:

• Batch type furnaces – where the workload is charged and discharged as a single unit or batch.
• Continuous furnaces – where the work enters and leaves the furnace in a continuous stream. These furnaces are favoured for high volume production of similar parts.

See also sealed quench.