Process for producing walking bar members for continuous casting

A process for producing a walking bar for continuous casting made of steel alloy of low weldability in the form of a flat tube having upper and lower opposed flat surfaces and a hollow interior over the entire length thereof, comprising:

• heating a tubular metal blank at a temperature of 550.degree. to 1250.degree. C;
• placing the heated blank between an upper die and a lower die of a press machine wherein a spacer having a height equal to a predetermined dimension to which the blank is to be compressed minus an amount of elastic restoration of the blank is placed between the upper die and the lower die;
• moving the upper and lower die toward the other to a position where the dies are spaced apart by the height of the spacer compressing the heated blank on upper and lower surfaces thereof over the entire length thereof by compressive plastic working which achieves a flattening ratio of about 1.0 to not greater than 3.0 pressing the blank into the flat tubular body with the upper and lower dies for a predetermined time period over the entire length of the blank;
• and
• machining at least one entire planar surface of the tubular body so as to smooth said surface, form a substantially planar surface, and reduce the wall thickness thereof between a hollow interior thereof and said smooth surface so as to increase a cooling effect of the wall, the thickness of which has been so reduced;
• the flattening ratio being represented by W/H wherein H is the minor outer diameter of the tubular body after plastic working and W is the major diameter of the tubular body after the plastic working;
• and
• minor side walls of said tubular body having a larger wall thickness than a major upper wall thereof which is machined and is made thinner.

A process for producing a walking bar for continuous casting made of steel alloy of low weldability in the form of a flat tube having upper and lower opposed flat surfaces and a hollow interior over the entire length thereof, comprising:

• heating a tubular metal blank at a temperature of 550.degree. to 1250.degree. C.;
• pressing the heated blank on upper and lower surface thereof over the entire length thereof by compressive plastic working which achieves a working ratio of up to 65% so as to compress the blank into a flat hollow tubular body;
• and
• machining at least one entire planar surface of the tubular body so as to smooth said surface, form a substantially planar surface and reduce the wall thickness thereof between a hollow interior thereof and said smooth surface so as to increase a cooling effect of the wall, the thickness of which has been so reduced, and the working ratio being represented by (D-H)/D.times.100 wherein D is the outside diameter of the blank before the plastic working and H is the minor outer diameter of the tubular body after the plastic working;
• and
• minor side walls of said tubular body having a wall thickness that differs from that of a major upper wall thereof which is machined and is made thinner.

A process for producing a walking bar for continuous casting mode of steel alloy of low weldability in the form of a flat tube having upper and lower opposed flat surfaces and a hollow interior over the entire length thereof, comprising:

• heating a tubular metal blank at a temperature of 550.degree. to 1250.degree. C.;
• pressing the heated blank on upper and lower surfaces thereof over the entire length thereof by compressive plastic working which achieves a flattening ratio of about 1.0 to not greater than 3.0 so as to compress the blank into a flat hollow tubular body;
• and
• machining at least one entire planar surface of the tubular body so as to smooth said surface, form a substantially planar surface, and reduce the wall thickness thereof between the hollow interior thereof and said smooth surface so as to increase a cooling effect of the wall, the thickness of which has been so reduced, the flattening ratio being represented by W/H wherein H is the minor outer diameter of the tubular body after plastic working and W is the major diameter of the tubular body after the plastic working;
• and
• minor side walls of the tubular body having a wall thickness that differs from that of a major upper wall thereof which is machined and is made thinner.