DEVICE AND METHOD FOR MANUFACTURING METAL CLAD STRIPS CONTINUOUSLY

Abstract

The device and method for manufacturing metal clad strip continuously provided by the present invention, combines casting, rolling and heat treatment used for the single material manufacture with the continuous and large-scale manufacture method for the clad strip, greatly improves the productivity of clad strip. The present invention can be used for manufacturing single-sided or double-sided clad strips with different thickness specifications, wherein the base layer material or the clad layer material can be selected in a wide range, including carbon steel, stainless steel, special alloy steel, titanium, copper and the like. In the present application, continuous casting and rolling clad strip is implemented, which decrease the energy consumption and costs.

Claims

1. A device for manufacturing metal clad strips continuously, comprising base material supplying equipment consisting of decoiler (1), pinch roll (2), shot blasting machine (3), welding equipment (4), welding pinch roll (5), induction heating apparatus (6), and guiding roll (7), wherein, base material strip (A) are transported by the base material supplying equipment through decoiler (1), pinch roll (2), shot blasting machine (3), welding equipment (4), welding pinch roll (5), induction heating apparatus (6) and guiding roll (7) to the mold (8) where the base material and molten steel are merged; the base material strip enters the mold along the middle inside from above, and pass through the mold from below, wherein the two inner walls of the mold being sealed with side seal plates; two tundishes (9) for casting molten steel is provided above the mold; the molten steel flows from tundish into the mold and contact with the two sides of the base material strip in the mold, so that a preliminary melt merging takes place; upon preliminary melt merging, the base material strip (A) forms a clad slab (B) which passes through the mold from below, and cooled at a secondary cooling section (10) by cooling-spray located at the outlet of the lower part of the mold; a leveling roll (11) is provided after the secondary cooling section, and a rolling mill (12) is provided after the leveling roll for rolling the clad slabs into clad strips (C) into different size and specification; an on-line cooling equipment (13) for the clad strips is provided after the rolling mill, a straightening machine (14) is provided at the exit of the on-line cooling equipment; the straightened clad strip is then cut to fixed length by a dividing shear (15) or is coiled by a coiler (16).

2. A method for manufacturing metal clad strips continuously by using the device for manufacturing metal clad strips continuously according to claim 1, comprising the following steps: 1) decoiling base material strip (A) having a thickness of 2˜20 mm with decoiler (1), while sending base material strip having a thickness of 21˜100 mm directly to the shot blasting machine (3) through pinch roll (2) for surface cleaning; then welding the shot-blasted base material strips head-to-tail by welding equipment (4) so as to supply the base material strips continuously; 2) sending the welded base material strips through welding pinch roll (5) to induction heating apparatus (6) for heating, wherein the induction heating apparatus is filled with nitrogen or argon protection atmosphere, the heating temperature ranges from 100° C. to 1200° C., the heating rate ranges from 1˜50° C./s depending on the thickness of the strip; the base material strips is selected from carbon steel, stainless steel, special alloy steel, titanium, copper and the like, the heating makes easier merging in the subsequent step of the base material strip and the molten clad layer, and accelerates melting of surface metal of base material strip; 3) sending the heated base material strips to mold (8) through guiding roll (7), where the base material strips enters the mold along the middle inside from above and pass through the mold from below at a rate of 0.1˜30 m/min; meanwhile, infusing one or two kind of molten clad melt in the tundish (9) into the mold with argon blowing on the mold surface to prevent the molten clad melt from oxidation; the temperature of the molten clad melt is 30˜150° C. higher than the melting point of the base material strips, and the molten clad melt is selected from carbon steel, stainless steel, special alloy steel, titanium, and copper; the molten clad melt having high temperature contacts the surface of the base material strip having low temperature, leading to slightly melt on the surface of the base material strip, and the molten clad melt is solidified on the surface of the base material strip having low temperature, so as to achieve a melting clad; with the molten clad melt being gradually solidified under the effect of the base material strip having low temperature and the copper plate of the mold, a clad slab (B) is formed, wherein a single-sided clad slab can be formed by one tundish, and a double-sided clad slab can be formed by two tundishes; 4) the clad slab (B) formed in the mold then passes through the mold from below and enters into secondary cooling section (10), where cooling water is sprayed on the upper and lower surfaces of the clad slab to further solidify the incompletely solidified clad slab, meanwhile the rapid cooling prevents the grains generated by surface solidification from growing and coarsening; 5) the clad slab (B) after cooling is leveled by leveling roll (11) and forwarded into rolling mill (12) to be rolled into clad strip (C) having different thickness ranging from 0.5 mm to 100 mm, where the clad interface of the clad strip is further compressed and deformed at high temperature during the rolling process, the microstructure of the clad interface structure recovers and recrystallizes, and recombination of the interface was promoted by grain growth and element diffusion under high temperature; 6) clad strip (C) after rolling is on-line cooled by on-line cooling equipment (13) according to the desired product performance, wherein the on-line cooling rate ranges from 1° C./s to 60° C./s, and the finish cooling temperature ranges from 50° C. to 600° C. depending on the thickness of the product; 7) the clad strip (C) after above cooling is transported to straightening machine (14) for straightening, which then cut in fixed length by dividing shear (15) or coiled by a coiler (16).

Description

FIGURE DESCRIPTION

[0030] FIG. 1 shows a schematic diagram of the device and method for manufacturing metal continuously according to the present invention, in which:

[0031] 1—decoiler, 2—pinch roll, 3—shot blasting machine, 4—welding equipment, 5—welding pinch roll, 6—induction heating apparatus, 7—guiding roll, 8—mold, 9—tundish, 10—secondary cooling section, 11—leveling roll, 12—rolling mill, 13—on-line cooling equipment, 14—straightening machine, 15—dividing shear, 16—coiler, A—base material strip, B—clad slab, C—clad strip.

DETAILED DESCRIPTION OF THE EMBODIMENTS

[0032] In the following, a device and method for manufacturing metal clad strips continuously provided by the present invention will be further described with reference to the drawings and embodiments.

EXAMPLE 1: DOUBLE-SIDED CLAD STRIPS

[0033] 1) Decoiling Q345B having a thickness of 20 mm with decoiler and sending it to shot blasting machine through pinch roll for surface cleaning, then welding the tail of shot-blasted strip to the head of the next shot-blasted strip by welding equipment so as to supply Q345B continuously;

[0034] 2) The welded Q345B is transported through welding pinch roll to induction heating apparatus to be heated, wherein the induction heating apparatus is filled with nitrogen for protection, the heating temperature is 850° C., the heating speed is 10° C./s;

[0035] 3) The heated Q345B passes through the mold along the middle inside of the mold at a speed of 3 m/min, and infusing the molten clad melt of 316L stainless steel in the two tundishes (9) into the mold with argon blowing on the mold surface to prevent the molten clad melt from oxidation, wherein the pouring temperature is 1550° C. The molten clad melt of 316L contacts the surface of the Q345B which surface is slightly melt, so as to achieve the primary melting clad of the clad layer and the base layer, and finally form a double-sided clad slab with a base layer of Q345B and clad layers of 316L, which has a thickness of 5+20+5 mm.

[0036] 4) The double-sided clad slab formed in the mold passes through the mold and enters into secondary cooling section, where cooling water is sprayed on the upper and lower surfaces of the clad slab to further solidify the incompletely solidified clad material, meanwhile rapid cooling prevents the grains generated by surface solidification from growing and coarsening;

[0037] 5) The cooled clad slab is transported to rolling mill at 1120° C. to be rolled into a double-sided clad strip with a thickness of 6 mm(1+4+1 mm), and the final rolling temperature is 1000° C. The rolled clad strip is cooled on-line, wherein the start cooling temperature is 950° C., the final cooling temperature is 540° C., and the cooling rate is 35° C./s;

[0038] 6) The cooled clad strip is transported to straightening machine for straightening, and the straightened clad strip is coiled on-line by a coiler.

[0039] EXAMPLE 2: SINGLE-SIDED CLAD STRIPS

[0040] 1) Decoiling AH36 carbon steel having a thickness of 40 mm with decoiler and sending it to shot blasting machine through pinch roll for surface cleaning, then welding the tail of shot-blasted strip to the head of the next shot-blasted strip by welding equipment so as to supply AH36 continuously;

[0041] 2) The welded carbon steel is transported through welding pinch roll to induction heating apparatus to be heated, wherein the induction heating apparatus is filled with nitrogen for protection, the heating temperature is 900° C., the heating speed is 15° C./s;

[0042] 3) The heated carbon steel passes through the mold along the middle inside of the mold at a speed of 1.8 m/min, and infusing the molten clad melt of 304L stainless steel in one of the tundishes into the mold with argon blowing on the mold surface to prevent the molten clad melt from oxidation, wherein the pouring temperature is 1580° C. The molten clad melt of 304L contacts the surface of the carbon steel which surface is slightly melt, so as to achieve the primary melting clad of the clad layer and the base layer, and finally form a single-sided clad slab with a base layer of AH36 carbon steel and clad layer of 304L, which has a thickness of 40+8 mm.

[0043] 4) The single-sided clad slab formed in the mold passes through the mold and enters into secondary cooling section, where cooling water is sprayed on the upper and lower surfaces of the clad slab to further solidify the incompletely solidified clad material, meanwhile rapid cooling prevents the grains generated by surface solidification from growing and coarsening;

[0044] 5) The cooled clad slab is transported to rolling mill at 1150° C. to be rolled into a single-sided clad strip with a thickness of 6 mm(5+1mm), and the final rolling temperature is 970° C. The rolled clad strip is cooled on-line, wherein the start cooling temperature is 910° C., the final cooling temperature is 420° C., and the cooling rate is 40° C./s;

[0045] 6) The cooled clad strip is transported to straightening machine for straightening, and the straightened clad strip is coiled on-line by a coiler.

[0046] The device and method for manufacturing metal clad strips continuously casting and rolling provided by the present invention, combines the continuous casting, rolling and heat treatment methods used for single material manufacture with the continuous and large-scale manufacture method of clad strip, greatly improves the productivity of clad strips and plates. The present invention can be used for manufacturing single-sided or double-sided clad plates and strips with different thickness specifications, wherein the base layer material or the clad material can be selected in a wide range, including carbon steel, stainless steel, special alloy steel, titanium, copper and the like. In the present application, continuous casting and rolling clad strip is implemented, which decrease the energy consumption and costs.