The explosive welding composition board is recovered the heat treating method and the equipment thereof of plasticity
Technical field
The present invention relates to a kind of heat treating method and equipment thereof, refer in particular to a kind of austenite stainless steel plate and mild steel plate need to recover plasticity behind explosive welding heat treating method and equipment thereof that is applied to.
Background technology
Austenitic stainless steel (later on " A stainless steel " replace)-soft steel composition board is by explosive welding the base material of soft steel and the stainless cover material of A to be welded together to make.In the process of explosive welding, as the A stainless steel of composite bed violent plastic flow can take place, thereby make the inside of cover material metal very big internal stress occur, cause intensive work hardening, its plasticity is reduced greatly.Therefore, when using such composite board manufacture equipment and needing bigger viscous deformation takes place, the cover material of composition board is that the stainless outside of A crackle can occur under tensile stress.So need before plastic forming, heat-treat, make it recover plasticity to composition board.
At present, great majority are produced the producer of " A stainless steel-soft steel explosive welding composition board ", the not thermal treatment that this class composition board is recovered plasticity.But also there is data once to inquire into, thinks and to carry out stress relief annealing thermal treatment to " A stainless steel-soft steel explosive welding composition board ", about about 600 ℃ of its annealing temperature that adopts.But, well-known, under such temperature (400~950 ℃), can separate out the carbide of Cr (chromium) in the A stainless steel, and stainless corrosion resistance nature is reduced, use the meaning of A stainless steel thereby lost as composite bed.If adopt the conventional whole normalizing treatment about 850 ℃, A stainless steel cover material corrosion resistance nature is reduced, and the plasticity of soft steel base material is reduced, A stainless steel cover material recovers not enough because of lower its plasticity of recrystallization temperature simultaneously.
Improve the stainless corrosion resistance nature of A, normally the A stainless steel is carried out solution treatment.And the solid solution temperature of A stainless steel routine is generally about 1150 ℃, and needs the insulation long period.But such heat treating method is applied to composition board, and overheated, the mechanical property organized of the soft steel base material of opposite side is reduced greatly.Therefore, also do not have at present to recover the plasticity of A stainless steel cover material under the prerequisite that a kind of proper heat treatment processing method can guarantee that other performance of composition board do not reduce.
Summary of the invention:
The technical issues that need to address of the present invention provide a kind of heat treating method that can recover the plasticity of A stainless steel-soft steel explosive welding composition board, and a kind of corresponding apparatus is provided.
Implementation method of the present invention is to comprise following processing step:
A adopts the rapid heating method that the A stainless steel cover material outer surface of composition board is heated rapidly, makes its surface be warmed up to 1000~1250 ℃ rapidly;
B keeps certain hour under said temperature, the temperature up to the inner bonding surface of composition board place rises to till 600~730 ℃;
C makes the cooling of composition board cover material outer side rapidly, is cooled to about 300~400 ℃ up to cover material;
D is cool to room temperature in air.
Rapid heating method described in the above-mentioned steps A comprises that employing has the flame heating of higher energy density, electrically contacts heating means such as heating, induction heating, and can use combinations wherein a kind of or two kinds.
The further improvement of the inventive method is: in whole heat treatment process, the outer side of soft steel base material is cooled off.As adopt that water spray or immersion are cooled off etc.
The equipment of realizing the inventive method comprises well heater, water cooler, support carrying roller.The support carrying roller is made up of spaced a series of carrying rollers and is driven by stepless speed-regulating motor, and its velocity of rotation has determined the translational speed of composition board at length direction; Well heater and water cooler are erected at the top of supporting carrying roller successively, and the just in time suitable composition board in the gap up and down between them is passed through, so that realize the continuous heating and cooling of composition board under the driving of supporting carrying roller.
The width of well heater and water cooler and the width of composition board adapt; The length of well heater is relevant with translational speed, cover material thickness and the Heating temperature etc. of heat-source energy density, composition board, so that the cover material of composition board is heated to 1000~1250 ℃ and is advisable; The length of water cooler is relevant with the translational speed of composition board, cover material thickness and heating and cooling temperature, so that composition board its cover material in sending to continuously approximately is cooled to be advisable about 300~400 ℃.
During thermal treatment, soft steel base material one side direction of A stainless steel-soft steel explosive welding composition board is placed down on the support carrying roller, carrying roller rotates under stepless speed-regulating motor drives, thereby drive A stainless steel-soft steel explosive welding composition board and enter well heater, the thermal source of the higher energy density in the well heater acts on downwards, and the outer surface that makes A stainless steel clad plate cover material is by rapid heating.The velocity of rotation of heat-source energy density, carrying roller and the length of well heater have determined the heated temperature and time of A stainless steel clad plate, have also just determined the height of composition board cover material (A stainless steel) with soft steel base material bonding surface place temperature.Therefore, after thermal source is fixing, can adjust the velocity of rotation that supports carrying roller according to the thickness of composition board and the length of well heater, thereby guarantee reasonable heated temperature and soaking time, and guarantee when the inner bonding surface of composition board place temperature rises to 600~730 ℃ of left and right sides, composition board shifts out the heating zone, enters the water cooler cooling.Water cooler can be set to the water spray cooling, and when the compound layer of A stainless steel outside surface cooled to 300~400 ℃ of left and right sides, composition board shifted out water cooler, naturally cools to room temperature in air.
The further improvement of equipment of the present invention is: the below of supporting carrying roller is provided with refrigerating unit, and described refrigerating unit is the wherein a kind of of water spraying cooler or the tank that springs up or both combinations.Also can only below the support carrying roller of well heater correspondence, water cooler be set.
The further improvement of equipment of the present invention is: be provided with pressure roller above supporting carrying roller.In whole heat treatment process, the pressure roller that supports the carrying roller top can reduce and prevent that composition board from deforming because of local heating and cooling, and can proofread and correct the composition board that has deformed.
The technical progress that the present invention obtains is:
Utilize method of the present invention that A stainless steel-soft steel explosive welding composition board is recovered plasticity thermal treatment, because Heating temperature has reached near the upper limit of A stainless steel solid solution temperature, although therefore this high-temperature time is very short, but also can play significantly solution treatment effect, promptly A stainless steel cover material one side of composition board has been carried out incomplete solution treatment; This incomplete solution treatment but is that recrystallize is handled completely; And soft steel base material one side has only been carried out the processing of part stress relief annealing.Because what adopt is method for rapid cooling, so in process of cooling, also can not produce the carbide of Cr.Therefore, this processing method not only makes the high-ductility state before A stainless steel cover material has returned to explosive welding, and has guaranteed that the corrosion resistance nature of A stainless steel cover material and soft steel base material mechanical property do not reduce.Through pliability test, do not find defectives such as crackle or interlayer cracking.
The present invention adopts to support carrying roller and drive composition board and moves, and has simplified the structure of equipment, has reduced equipment manufacturing cost.
The type of cooling of the present invention is to adopt composition board is carried out compound cooling of while in two sides up and down: composition board base material one side (below) adopts water spray refrigerative mode, it can prevent that the temperature rise of soft steel base material is too fast, too high, is the stainless solution treatment time of A thereby prolong the composition board cover material; Composition board cover material one side (top) also adopts water spray refrigerative mode, makes the cover material fast cooling and rapidly by 400~950 ℃ temperature range, in case can separate out the carbide of Cr in the A stainless steel stainless corrosion resistance nature is reduced.Therefore, make base material and cover material all obtain needed good performance.
The effect of pressure roller of the present invention is to prevent that composition board from deforming because of local heating and cooling, and can proofread and correct the composition board that has deformed.
Description of drawings:
Fig. 1 is a heat treatment cycle curve of the present invention;
Fig. 2 is the synoptic diagram of equipment of the present invention.
Wherein: 1, composition board, 2, water cooler, 3, well heater, 4, pressure roller, 5, support carrying roller, 6, cooling trough.
Embodiment:
Below in conjunction with accompanying drawing the present invention is described in further details:
Shown in Figure 1, it is the A stainless steel cover material outside near any process curve of surface.Because heating means of the present invention are the rapid heating under the nonequilibrium situations, so the heat treatment cycle curve of the each point of the following different depths of steel surface is inequality, but its shape is all similar to Fig. 1.The explanation of this process curve, the A stainless steel cover material of composition board is in the heating extremely fast of quilt below 1000 ℃, to 1000~1250 ℃ of heat up and become slow a little, after reaching top temperature, begin to keep or slowly descend, when entering water cooler, temperature just sharply descends.Though this pyroprocess time is very short,, therefore also can play the effect of part solution treatment owing to reached near the upper limit of A stainless steel solid solution temperature.
The equipment of realizing above-mentioned process curve comprises oxyacetylene torch well heater 3, water spraying cooler 2, supports carrying roller 5.Support carrying roller 5 is made up of spaced a series of carrying rollers and is driven by stepless speed-regulating motor; Well heater 3 and water cooler 2 are erected at the top of supporting carrying roller 5 successively, and fired heater 3 is that the plurality of nozzles of parallel arranged is formed; Water spraying cooler 2 is made up of some water jets.
One embodiment of the present of invention are that, 400mm wide with 200mm is long, body material is that 20mm thick No. 20 soft steel, composite bed cover material are that the thick A stainless steel of 3mm is an experiment material.Here fired heater 3 is provided with three row's nozzles, and water spraying cooler 2 is provided with 6 row's nozzles, and each nozzle can be controlled respectively; The width of the well heater 3 and the nozzle arrangement of water cooler 2 is corresponding with the width of clad steel plate.Be provided with cooling trough 6 below support carrying roller 5, cooling trough 6 is provided with water spraying cooler; Above supporting carrying roller 5, be provided with the pressure roller 4 that height-adjustable smoothing composition board is used.
During processing, the soft steel base material that makes A stainless steel-soft steel explosive welding composition board 1 is to being placed down on the supporting bracket roller 5, supporting carrying roller 5 rotates under the driving of stepless speed-regulating motor, enter in the heated perimeter of well heater 3 thereby drive A stainless steel-soft steel explosive welding composition board 1, the composition board cover material is that the stainless outer surface of A is by rapid heating.After the heat-source energy density of well heater is adjusted, when the velocity of rotation that supports carrying roller 5 should be adjusted into the temperature that is heated temperature to 1000~1250 ℃, the inner bonding surface of composition board place when the composition board cover material and rises to 600~730 ℃ of left and right sides, this part heated composition board just in time shifts out the heating zone, and enters the water cooler cooling.The length of the cooling zone of water cooler should guarantee that composition board just in time shifts out water cooler, cools off then, up to room temperature when the compound layer of A stainless steel outside surface cools to 400 ℃ of left and right sides in air.
Other embodiment of the well heater of aforesaid device also has: electrically contact heating, induction heating, oxygen-natural gas flame heating, oxygen-type of heating such as gas flame heating.
What of the well heater 3 of aforesaid device and the nozzle of water cooler 2 are relevant with heat-source energy density, heating and cooling temperature and the productivity etc. of the thermal conductivity of the thickness of the composition board cover material of needs heating, metal, well heater.Therefore can establish more rows' nozzle, as the nozzle of 6 row's well heaters, the nozzle of 10 row's water coolers.