Control of continuous casting operation

Claim 1

A method of continuously casting a continuous rod comprising the steps of: a. continuously introducing molten metal into the inlet end of the cavity of an open-ended continuous casting mold; b. said mold including a first zone adjacent said inlet end having a relatively low heat transfer capacity, a second zone immediately adjacent said first zone having a relatively high heat transfer capacity, and a third zone adjacent said second zone terminating in an open outlet end; c. advancing said molten metal into said first zone, the heat transfer characteristics of said first zone being operative to substantially prevent any metal solidification therein; d. advancing said molten metal into said second zone, the high heat transfer characteristics of said second zone being operative to cause solidification of a thin layer of said metal at first immediately at the juncture of said first and second zone and then progressively in the direction of said third zone whereby a thin layer of said molten metal is formed coextensively of said second zone; e. advancing said rod intermittently in fixed predetermined increments at fixed predetermined time intervals, said increments being equal to the length of said second zone whereby said thin layer of said solidified metal formed in said second zone is advanced progressively into said third zone and the molten metal advancing from said first zone follows the advance of said thin layer to progressively fill said second zone immediately behind said advancing thin layer and to thereby progressively form a new thin solidified layer coextensively of said second zone cavity surface, said intervals being of sufficient duration to permit the forward axial end of said newly formed thin layer to weld to the solidified metal in said third zone; f. continuously monitoring the change in mold temperature in a region between the beginning of said first zone and the beginning of said third zone, said mold temperature normally fluctuating between a maximum temperature and a minimum temperature during said time interval; g. stopping the advance of said rod for a fixed predetermined dwell period when said mold temperature falls below said minimum temperature which indicates that said newly formed thin layer has failed to weld to the solidified metal in said third zone, said dwell period being longer than said fixed time intervals, to permit said layer, which previously failed to weld, to weld to the solidified metal in said third zone, and h. resuming the advance of said rod at the completion of said dwell period in said fixed predetermined increments at said fixed predetermined time intervals.

Claim 2

A method of continuously casting a continuous rod comprising the steps of: a. continuously introducing molten metal into the inlet end of the cavity of an open-ended continuous casting mold; b. said mold including a first zone adjacent said inlet end having a relatively low heat transfer capacity, a second zone immediately adjacent said first zone having a relatively high heat transfer capacity, and a third zone adjacent said second zone terminating in an open outlet end; c. advancing said molten metal into said first zone, the heat transfer characteristics of said first zone being operative to substantially prevent any metal solidification therein; d. advancing said molten metal into said second zone, the high heat transfer characteristics of said second zone being operative to cause solidification of a thin layer of said metal at first immediately at the juncture of said first and second zone and then progressively in the direction of said third zone whereby a thin layer of said molten metal is formed coextensively of said second zone; e. advancing said rod intermittently in fixed predetermined increments at fixed predetermined time intervals, said increments being equal to the length of said second zone whereby said thin layer of said solidified metal formed in said second zone is advanced progressively into said third zone and the molten metal advancing from said first zone follows the advance of said thin layer to progressively fill said second zone immediately behind said advancing thin layer and to thereby progressively form a new thin solidified layer coextensively of said second zone cavity surface, said intervals being of sufficient duration to permit the forward axial end of said newly formed thin layer to weld to the solidified metal in said third zone; f. continuously monitoring the change in mold temperature in a region between the beginning of said first zone and the beginning of said third zone, said mold temperature normally fluctuating between a maximum temperature and a minimum temperature during said time interval; g. stopping the advance of said rod for a fixed predetermined dwell period when said mold temperature falls below said minimum temperature which indicates that said newly formed thin layer has failed to weld to the solidified metal in said third zone, said dwell period being longer than said fixed time intervals, to permit said layer, which previously failed to weld, to weld to the solidified metal in said third zone, and h. resuming the advance of said rod at the completion of said dwell period in said fixed predetermined increments at said fixed predetermined time intervals.

Claim 3

A method of coNtinuously casting a continuous rod comprising the steps of: a. continuously introducing molten metal into the inlet end of the cavity of an open-ended continuous casting mold; b. said mold including a first zone adjacent said inlet end having a relatively low heat transfer capacity, a second zone immediately adjacent said first zone having a relatively high heat transfer capacity, and a third zone adjacent said second zone terminating in an open outlet end; c. advancing said molten metal into said first zone, the heat transfer characteristics of said first zone being operative to substantially prevent any metal solidification therein; d. advancing said molten metal into said second zone, the high heat transfer characteristics of said second zone being operative to cause solidification of a thin layer of said metal at first immediately at the juncture of said first and second zones and then progressively in the direction of said third zone whereby a thin layer of said molten metal is formed coextensively of said second zone; e. advancing said rod intermittently in fixed predetermined increments at fixed predetermined time intervals, said increments being equal to the length of said second zone whereby said thin layer of said solidified metal formed in said second zone is advanced progressively into said third zone and the molten metal advancing from said first zone follows the advance of said thin layer to progressively fill said second zone immediately behind said advancing thin layer and to thereby progressively form a new thin solidified layer coextensively of said second zone cavity surface, said intervals being of sufficient duration to permit the forward axial end of said newly formed thin layer to weld to the solidified metal in said third zone; f. continuously monitoring the mold temperature in the vicinity of said juncture, said mold temperature normally fluctuating between a maximum temperature and a minimum temperature during said time interval; g. stopping the advance of said rod for a fixed predetermined dwell period when said mold temperature falls below a predetermined temperature, said predetermined temperature being below said minimum temperature, which indicates that said newly formed thin layer has failed to weld to the solidified metal in said third zone, said dwell period being longer than said fixed time intervals, to permit said layer, which previously failed to weld, to weld to the solidified metal in said third zone, and h. resuming the advance of said rod at the completion of said dwell period in said fixed predetermined increments at said fixed predetermined time intervals.

Claim 4

A method of coNtinuously casting a continuous rod comprising the steps of: a. continuously introducing molten metal into the inlet end of the cavity of an open-ended continuous casting mold; b. said mold including a first zone adjacent said inlet end having a relatively low heat transfer capacity, a second zone immediately adjacent said first zone having a relatively high heat transfer capacity, and a third zone adjacent said second zone terminating in an open outlet end; c. advancing said molten metal into said first zone, the heat transfer characteristics of said first zone being operative to substantially prevent any metal solidification therein; d. advancing said molten metal into said second zone, the high heat transfer characteristics of said second zone being operative to cause solidification of a thin layer of said metal at first immediately at the juncture of said first and second zones and then progressively in the direction of said third zone whereby a thin layer of said molten metal is formed coextensively of said second zone; e. advancing said rod intermittently in fixed predetermined increments at fixed predetermined time intervals, said increments being equal to the length of said second zone whereby said thin layer of said solidified metal formed in said second zone is advanced progressively into said third zone and the molten metal advancing from said first zone follows the advance of said thin layer to progressively fill said second zone immediately behind said advancing thin layer and to thereby progressively form a new thin solidified layer coextensively of said second zone cavity surface, said intervals being of sufficient duration to permit the forward axial end of said newly formed thin layer to weld to the solidified metal in said third zone; f. continuously monitoring the mold temperature in the vicinity of said juncture, said mold temperature normally fluctuating between a maximum temperature and a minimum temperature during said time interval; g. stopping the advance of said rod for a fixed predetermined dwell period when said mold temperature falls below a predetermined temperature, said predetermined temperature being below said minimum temperature, which indicates that said newly formed thin layer has failed to weld to the solidified metal in said third zone, said dwell period being longer than said fixed time intervals, to permit said layer, which previously failed to weld, to weld to the solidified metal in said third zone, and h. resuming the advance of said rod at the completion of said dwell period in said fixed predetermined increments at said fixed predetermined time intervals.

Claim 6

A method of continuously casting a continuous rod comprising the steps of: a. continuously introducing molten metal into the inlet end of the cavity of an open-ended continuous casting mold; b. said mold including a first zone adjacent said inlet end having a relatively low heat transfer capacity, a second zone immediately adjacent said first zone having a relatively high heat transfer capacity, and a third zone adjacent said second zone terminating in an open outlet end; c. advancing said molten metal into said first zone, the heat transfer characteristics of said first zone being operative to substantially prevent any metal solidification therein; d. advancing said molten metal into said second zone, the high heat transfer characteristics of said second zone being operative to cause solidification of a thin layer of said metal at first immediately at the juncture of said first and second zone and then progressively in the direction of said third zone whereby a thin layer of said molten metal is formed coextensively of said second zone; and e. advancing said rod continuously but in fixed increments of 0.1 to 1.5 times the diameter of the rod being cast aT fixed cycle time intervals of about 0.15 to 1.1 seconds, said increments being equal to the length of said second zone whereby said thin layer of said solidified metal formed in said second zone is advanced progressively into said third zone and the molten metal advancing from said first zone follows the advance of said thin layer to progressively fill said second zone immediately behind said advancing thin layer and to thereby progressively form a new thin solidified layer coextensively of said second zone cavity surface, said rod being at rest for a time of 33 percent to 65 percent of said cycle time interval to permit the forward axial end of said newly formed thin layer to weld to the solidified metal in said third zone; f. continuously monitoring the change in mold temperature in a region between the beginning of said first zone and the beginning of said third zone, said mold temperature normally fluctuating between a maximum temperature and a minimum temperature during said time interval; g. stopping the advance of said rod for a fixed predetermined dwell period of about 2 to 10 seconds when said mold temperature falls below said minimum temperature which indicates that said newly formed thin layer has failed to weld to the solidified metal in said third zone to permit said layer, which previously failed to weld, to weld to the solidified metal in said third zone, and h. resuming the advance of said rod at the completion of said dwell period in said fixed predetermined increments at said fixed predetermined time intervals.

Claim 7

A method of continuously casting a continuous rod comprising the steps of: a. continuously introducing molten metal into the inlet end of the cavity of an open-ended continuous casting mold; b. said mold including a first zone adjacent said inlet end having a relatively low heat transfer capacity, a second zone immediately adjacent said first zone having a relatively high heat transfer capacity, and a third zone adjacent said second zone terminating in an open outlet end; c. advancing said molten metal into said first zone, the heat transfer characteristics of said first zone being operative to substantially prevent any metal solidification therein; d. advancing said molten metal into said second zone, the high heat transfer characteristics of said second zone being operative to cause solidification of a thin layer of said metal at first immediately at the juncture of said first and second zone and then progressively in the direction of said third zone whereby a thin layer of said molten metal is formed coextensively of said second zone; and e. advancing said rod continuously but in fixed increments of 0.1 to 1.5 times the diameter of the rod being cast aT fixed cycle time intervals of about 0.15 to 1.1 seconds, said increments being equal to the length of said second zone whereby said thin layer of said solidified metal formed in said second zone is advanced progressively into said third zone and the molten metal advancing from said first zone follows the advance of said thin layer to progressively fill said second zone immediately behind said advancing thin layer and to thereby progressively form a new thin solidified layer coextensively of said second zone cavity surface, said rod being at rest for a time of 33 percent to 65 percent of said cycle time interval to permit the forward axial end of said newly formed thin layer to weld to the solidified metal in said third zone; f. continuously monitoring the change in mold temperature in a region between the beginning of said first zone and the beginning of said third zone, said mold temperature normally fluctuating between a maximum temperature and a minimum temperature during said time interval; g. stopping the advance of said rod for a fixed predetermined dwell period of about 2 to 10 seconds when said mold temperature falls below said minimum temperature which indicates that said newly formed thin layer has failed to weld to the solidified metal in said third zone to permit said layer, which previously failed to weld, to weld to the solidified metal in said third zone, and h. resuming the advance of said rod at the completion of said dwell period in said fixed predetermined increments at said fixed predetermined time intervals.