The process of continuous casting and rolling wrought magnesium alloy thin plate and band
Technical field:
The present invention relates to technical field of nonferrous metal processing, a kind of process of continuous casting and rolling wrought magnesium alloy thin plate and band.
Background technology:
At present, in the process of deformable magnesium alloy sheet, employing enters batching and is smelted into magnesium alloy in the smelting furnace; Alloy melt becomes flat ingot blank through semi-continuous casting; After milling face, flaw detection, sawing again; Again through homogenizing annealing, heat, be rolled into slab; And then through warm-rolling/cold rolling one-tenth thin plate.I.e. employing batching and melting → semi-continuous casting (flat ingot blank) → mill face → flaw detection → sawing → homogenizing annealing → heating → hot rolling → warm-rolling/cold rolling → finishing → surface treatment → goods to pack operations such as warehouse-in.This process flow process is longer, and slab is difficult to plastic working at normal temperatures, and yield rate is low, and 1.0mm magnesium alloy sheet yield rate only is about 20%; And have that energy resource consumption is big, metal loss is many, cost is crossed high shortcoming.And this method can only one chip production, can not be as copper, aluminium, steel belt method continuous rolling, thereby production efficiency is very low.
Summary of the invention:
In order to overcome the deficiencies in the prior art, the invention provides a kind of process of continuous casting and rolling wrought magnesium alloy thin plate and band, make its shortened process greatly, improve yield rate (1.0mm magnesium alloy sheet yield rate can reach more than 60%), cut down the consumption of energy, and significantly improve the plasticity of magnesium alloy, solved the difficult problem that magnesium alloy is difficult to plastic working at normal temperatures, for magnesium alloy belt type rolling has been started advantage.
For achieving the above object, the present invention adopts following technical scheme:
The process of described continuous casting and rolling wrought magnesium alloy thin plate and band, employing are prepared burden and are founded → distributor → continuous casting and rolling → warm-rolling → finishing → surface treatment → goods packing; Utilize melt to consolidate the characteristic that is shaped under the state and stands rolling deformation half, solidification temperature range, thermal capacitance and flowability thereof according to different trade mark alloys, different in width and thickness requirement at goods, design different distributors, control the proterties of magnesium alloy, raw material is dropped into the induction type smelting furnace until batching fusing fully " solidifying-deformed area "; Magnesium alloy fused mass pumps into distributor from smelting furnace through infusion pump, and magnesium alloy fused mass flows to the roll gap between two rolls of casting and rolling machine configuration equably through distributor; Thereby the realization metal, is directly finished through a continuous casting and rolling operation passage to the plate/band with deformation state from melt.
The process of described continuous casting and rolling wrought magnesium alloy thin plate and band, magnesium alloy fused mass also can enter distributor through infusion pipeline from smelting furnace; The temperature of magnesium alloy fused mass when coming out of the stove will be controlled between 700~780 ℃, and it all adopts the N of 1~2 ‰ SF6 from the smelting furnace to the export distributor
2Protective gas is protected.
The process of described continuous casting and rolling wrought magnesium alloy thin plate and band is fed into smelting furnace with raw material, and its smelting furnace also can be a resistance-type.
The process of described continuous casting and rolling wrought magnesium alloy thin plate and band, the distributor that adopts fan-shaped casing and form in its continuous casting and rolling by the refractory material compacting sintering, the outlet size of distributor is 3.0~10.0 * 300~1600mm, its inner chamber has 2~9 branching blocks, and be installed on the casting and rolling machine roll gap central horizontal face, magnesium alloy fused mass flows to the roll gap between two rolls of casting and rolling machine configuration equably through distributor, the gap between distributor and the roll is 0.1-1.2mm.
The process of described continuous casting and rolling wrought magnesium alloy thin plate and band, its casting and rolling machine disposes two inner-cooled rolls, its inside is connected with cooling water, cooling water inlet temperature 15-25 ℃, outlet temperature is not more than 40 ℃, the installation of roll can be that back hectare formula is installed, and the caster angle degree is 5-15 °, and the roll gap between two rolls is 2.0-10.0mm; Mill speed is 800-1500mm/min.
Technical scheme the present invention has following good effect owing to adopted as mentioned above:
The process of this continuous casting and rolling wrought magnesium alloy thin plate and band, can save milling 5 procedures such as face, flaw detection, homogenizing annealing, sawing and heating in the former technology, to cast and hot rolling is merged into a procedure and finishes, promptly adopt: prepare burden and found → distributor → continuous casting and rolling (plate/band) → warm-rolling → finishing → surface treatment → operations such as goods packing delivery.Adopt the present invention can solve the defective that existing process is made, thereby the characteristics that have the flow process weak point, improve yield rate (1.0mm magnesium alloy sheet yield rate can reach more than 60%), energy consumption are low, metal loss is few, cost only are 50% of existing process making.And significantly improve the plasticity of magnesium alloy, solved the difficult problem that magnesium alloy is difficult to plastic working at normal temperatures, for magnesium alloy belt type rolling has been started precondition.
The inventive method is to utilize melt to be shaped under semisolid and stand rolling deformation.Solidification temperature range, thermal capacitance and flowability thereof according to different trade mark alloys, different in width and thickness at goods, design different distributors, with the proterties of control magnesium alloy " solidifying-deformed area ", thereby the realization metal, is directly finished by a continuous casting and rolling passage to the plate/band with deformation state from melt.
Casting and rolling machine disposes two inner-cooled rolls in this technology, its inside is connected with cooling water, 15~25 ℃ of cooling water inlet temperatures, outlet temperature is not more than 40 ℃, therefore when magnesium alloy fused mass contacts with roll because of cooling off crystallization rapidly, but because the impact of follow-up superheated melt, cause that " colony " of crystallization just is broken to cause more nucleus, thereby produce the metal turbulent flow, under the effect of its metal turbulent flow, solidify-forward position, deformed area formation semisolid, when metal arrives two roller gap center lines then, because the metal turbulent flow, the triple role of cooling and pressure processing formation plate/band has ultrafine-grained (UFG) microstructure (about average grain size 20 μ m) rapidly, and significantly improves the plasticity of magnesium alloy, solve the difficult problem that magnesium alloy is difficult to plastic working at normal temperatures, improved yield rate.
The wrought magnesium alloy thin plate and band material that adopts the inventive method to produce can be widely used in mobile phone, digital camera, notebook computer casing; The hand-held tool shell; Fascia, automobile variable speed case lid, automobile door lining and deck; Aspects such as folded formula magnesium cell sheet and aircraft internal partition, food casing.
The drawing explanation:
Fig. 1 is the process chart of continuous casting and rolling wrought magnesium alloy thin plate and band:
The specific embodiment one:
To produce wrought magnesium alloy A231, specification is: the sheet material of 6.0 * 600 * 2500mm is example:
Batching and founding: at first weigh respectively by weight ratio, drop into the induction type smelting furnace until batching fusing fully.Adopt the N of 1 ‰ SF6 during melting
2Protective gas is protected.
Distributor: magnesium alloy fused mass pumps into distributor from smelting furnace through infusion pump, 730 ℃ of magnesium alloy fused mass temperature, and the distributor inner chamber has 4 branching blocks, and export distributor is of a size of 6.6 * 600mm; Gap between distributor and the roll is 0.3mm.All adopt the N of 1 ‰ SF6 to export distributor from smelting furnace
2Protective gas is protected, and magnesium alloy fused mass flows to the roll gap between two rolls of casting and rolling machine configuration equably through distributor.
Continuous casting and rolling (plate/band): adopt continuous casting machine to carry out continuous casting and rolling.Casting and rolling machine disposes two inner-cooled rolls, and its inside is connected with cooling water, 15 ℃ of cooling water inlet temperatures, and outlet temperature is not more than 40 ℃, and roll form is that back hectare formula is installed, and the caster angle degree is 15 °, and the roll gap between two rolls is 5.8mm; Mill speed is 800mm/min.Therefore when magnesium alloy fused mass contacts with roll because of cooling off crystallization rapidly, but because the impact of follow-up superheated melt, cause that the colony of crystallization just is broken to cause more nucleus, thereby produce the metal turbulent flow, under the effect of its metal turbulent flow, " solidify-deformed area " forward position and form semisolid, when metal arrives two roller gap center lines then, because the metal turbulent flow, cooling and the triple role of pressure processing form sheet material and have ultrafine-grained's (average grain size is about 20 μ m) rapidly, and then casting becomes the sheet material of 6.0 * 600 * 2500mm.
Finishing: adopt multi-roll straightening machine to carry out finishing, according to the contract require again to adopt cutter to shear.
Surface treatment: adopt skin grinder to carry out surface treatment.
The specific embodiment two:
The band that is of a size of 1.0 * 1000 * 2000mm with production wrought magnesium alloy MB3 is an example:
Batching and founding: at first weigh respectively by weight ratio, drop into the resistance-type smelting furnace until batching fusion fully.Adopt the N of 2 ‰ SF6 during melting
2Protective gas is protected.
Distributor: magnesium alloy fused mass enters distributor through the stove fluid hole by liquid-transport pipe-line from smelting furnace, 760 ℃ of magnesium alloy fused mass temperature, and the distributor inner chamber has 7 branching blocks, and export distributor is of a size of 5.0 * 1000mm; Gap between distributor and the roll is 1.0mm.All adopt the N of 2 ‰ SF6 to export distributor from smelting furnace
2Protective gas is protected, and magnesium alloy fused mass flows to the roll gap between two rolls of casting and rolling machine configuration equably through distributor.
Continuous casting and rolling band: adopt continuous casting machine to carry out continuous casting and rolling.Casting and rolling machine disposes two inner-cooled rolls, and its inside is connected with cooling water, 25 ℃ of cooling water inlet temperatures, and outlet temperature is not more than 40 ℃, and roll form is vertically to install up and down, and the roll gap between two rolls is 3.8mm; Mill speed is 1500mm/min.Therefore when magnesium alloy fused mass contacts with roll because of cooling off crystallization rapidly, but because the impact of follow-up superheated melt, cause that the colony of crystallization just is broken to cause more nucleus, thereby produce the metal turbulent flow, under the effect of its metal turbulent flow, " solidify-deformed area " forward position and form semisolid, when metal arrives two roller gap center lines then, because the metal turbulent flow, cooling and the triple role of pressure processing form the ultrafine-grained (UFG) microstructure (average grain size is about 20 μ m) that plate/band had rapidly, and then casting becomes the sheet material of 4.0 * 1000 * 1000mm.
Warm-rolling: the slab that blank heating to 300 ℃ is rolled into 2.0 * 1000 * 2000mm on three-high mill (diameter 750/400/750mm), through being heated to 350 ℃, on three-high mill (diameter 750/750/750mm), roll into the strip of 1.0 * 1000 * 2000mm again.
Finishing: adopt 19 roller straighteners to carry out finishing, according to the contract require again to adopt cutter to shear.
Surface treatment: adopt skin grinder to carry out surface treatment.