Roll and process for producing same

A process for producing a roll comprising horizontally arranging a core body made of a cast steel or steel based Adamite containing from 0.5 to 2.5% C, said core body having at least one circumferential groove in its circumferential surface;

• feeding a consumable electrode wire into at least one of said grooves while rotating said core body;
• and building up an Adamite deposited metal over the surfaces of said at least one groove, said Adamite deposited metal containing 1.5 to 2.5% C and being built-up by electro-slag welding to a radial thickness or from 20 mm to 1/10 of the original diameter of said core body.

A process for producing a roll by electro-slag-welding comprising using a start-tab having a top surface which is sloped upwards towards the outer circumference of said core body, as viewed in the transverse cross section of said core body, when starting welding, said start-tab being made of graphite.

A process for producing a roll by electro-slag-welding comprising converting flux into molten slag by using a consumable electrode wire at the beginning or completion of welding;

• then interrupting the feed of said consumable electrode wire;
• maintaining said molten slag at a high temperature for a given period of time by the use of non-consumable electrode;
• and thereafter proceeding with welding by the use of a consumable electrode wire.

A process for producing a roll comprising horizontally arranging a core body made of a cast steel or steel based Adamite and containing from 0.5 to 2.5% C, said core body having at least one circumferential groove in its circumferential surface;

• depositing in said at least one circumferential groove by electro-slag welding a metal consisting essentially of by weight 1.5 to 2.5% C, 0.2 to 1.0% Si, 0.5 to 1.0% Mn, 0.5 to 3.0% Cr and 0.2 to 3.0% Mo, the balance being essentially Fe and inevitable impurities;
• and subjecting the articles so formed to heat treatment at a temperature of from 500.degree. to 700.degree. C.

A process for producing a roll comprising:

• horizontally arranging a core body made from a cast steel or steel based Adamite containing from 0.5 to 2.5% C, said core body having at least one circumferential groove in its circumferential surface;
• and depositing by electro-slag welding sufficient metal to fill said at least one groove, said metal containing 1.5 to 2.5% C by weight, the radial thickness of the metal in said groove being from 20 mm to 1/10 of the original diameter of said core body.

In an electro-slag welding process for depositing a metal into a circumferential groove in the circumferential surface of a core body in which (1) a start-tab is inserted into said circumferential groove, (2) electro-slag welding is initiated by generating an arc between a consumable electrode wire and said start tab, (3) electro-slag welding is continued by feeding a consumable electrode to said groove and rotating said core body, and (4) said start-tab is removed from said groove prior to termination of electro-slag welding, the improvement wherein said start-tab defines a top surface, said top surface sloping upwardly toward the outer circumference of said core body as viewed in the transverse cross section of said core body when electro-slag welding is initiated, said start-tab being made from graphite.

In an electro-slag welding process for depositing a metal into a circumferential groove in the circumferential surface of a core body in which (1) a start-tab is inserted into said circumferential groove, (2) electro-slag welding is initiated by generating an arc between a consumable electrode wire and said start-tab, flux adjacent said arc being converted into molten slag by the heat produced by said arc, and (3) electro-slag welding is continued by rotating said core body and feeding further consumable electrode wire to said circumferential groove, the improvement for preventing improper fusion of metal in said groove at the initial stage of electro-slag welding comprising withdrawing said consumable electrode wire from said slag after said flux is converted into molten slag, maintaining the molten slag at a high temperature for a time sufficient to prevent improper fusion during the initial stage of electro-slag welding by the use of a non-consumable electrode, and thereafter proceeding with electro-slag welding by the use of said consumable electrode wire.

A roll comprising a core body of a cast steel-based Adamite containing from 0.5 to 2.5% C, said core body having at least one circumferential groove in its circumferential surface, and a deposited metal build-up over the surfaces of said at least one groove, said deposited metal build-up being produced by electro-slag welding and consisting essentially of by weight 1.5 to 2.5% C, 0.2 to 1.0% Si, 0.5 to 1.0% Mn, 0.5 to 3.0% Cr and 0.2 to 3.0% Mo, the balance being essentially Fe and inevitable impurities, said deposited metal having been subjected to a heat treatment at a temperature between 500.degree. and 700.degree. C.

A roll comprising a core body made of a cast steel or steel-based Adamite containing 0.5 to 2.5% C, said core body having at least one circumferential groove in its circumferential surface, and a deposited metal build-up on the surfaces of said at least one groove, said deposited metal build-up being produced by electro-slag welding and containing 1.5 to 2.5% C, said deposited metal build-up having a radial thickness of 20 mm to 1/10 of the original diameter of said core body.