Casting steel strip

Apparatus for casting steel strip comprising:

• a pair of generally horizontal casting rolls forming a nip between them;
• a metal delivery system to deliver molten steel into the nip between the casting rolls to form a casting pool of molten steel supported on the rolls;
• a cooling system to chill the casting rolls;
• a drive system to rotate the casting rolls in mutually opposite directions to produce a cast strip delivered downwardly from the nip;
• a strip guide to guide the strip delivered downwardly from the nip through a transit path which takes it away from the nip;
• a first enclosure to confine the strip throughout said transit path which enclosure is sealed to control ingress of atmospheric air;
• a second enclosure to receive strip after it has passed through the first enclosure which second enclosure is also sealed to control ingress of atmospheric air;
• and
• a water spray operable to spray water into the second enclosure in the form of a fine mist so as to generate steam within the second enclosure.

A method of continuously casting steel strip comprising:

• supporting a casting pool of molten steel on one or more chilled casting surfaces;
• moving the chilled casting surface or surfaces to produce a solidified steel strip moving away from the casting pool;
• providing a first enclosure and a second enclosure to surround the solidified steel strip as the strip moves away from the casting pool such that the strip can be exposed to separate atmospheric conditions in the first enclosure and thereafter the second enclosure;
• sealing the first and second enclosures to restrict ingress of atmospheric air;
• passing the solidified strip through the first enclosure and thereafter the second enclosure;
• and
• introducing water into the second enclosure to produce an increased level of hydrogen gas within the second enclosure while tending to avoid liquid water contact with the steel strip.

Apparatus for casting steel strip comprising:

• a pair of generally horizontal casting rolls forming a nip between them;
• a metal delivery system to deliver molten steel into the nip between the casting rolls to form a casting pool of molten steel supported on the rolls;
• a cooling system to chill the casting rolls;
• a drive system to rotate the casting rolls in mutually opposite directions to produce a cast strip delivered downwardly from the nip;
• at least one strip guide to guide the strip delivered downwardly from the nip through a transit path which takes it away from the nip;
• a first enclosure sealed to control ingress of atmospheric air and surrounding the strip through at least part of said transit path;
• a second enclosure separate from the first enclosure also sealed to control ingress of atmospheric air and capable of receiving the strip after it has passed through the first enclosure;
• and
• at least one water spray operable to spray water into the second enclosure to produce an increased level of hydrogen gas within the second enclosure while tending to avoid liquid water contact with the steel strip.