Fusing

Wrought-iron and steel plates, and structures of all sorts, are now cut up by oxygen, and it is a process based on the fact that a jet of oxygen directed upon a previously heated spot of metal ignites it, with the result that the metal is rapidly taken away in the form of an oxide. The cutting operation is as follows: The surface of the metal to be cut is first heated by a mixed jet of oxygen and coal gas. When this part has been brought to a state of incandescence, a fine cutting jet of oxygen is discharged upon it. This immediately produces combustion of the metal with the resulting formation of iron oxide. The jet of oxygen is made sufficiently strong to blow away the iron oxide in front of it, with the result that a clean narrow cut is effected through the metal at a speed of travel similar to hot sawing. When cutting material more than 6 in. in thickness, hydrogen is used instead of coal gas.