Background technology
Mental package is the important component part of China's packaging industry, and its output value accounts for 10% of China's packaging industry, is widely used in the aspects such as food, medicine, industrial packaging.In mental package, taking coating tinplate packaging as main, major product is tin graphed sheet goods, pop can, inhalator jar, food cans, all kinds of bottle cap and industrial chemical barrel and steel drum according to investigations.China now has tinplate built-up tin manufacturing line approximately more than 500 bars, approximately 6,000,000,000 of the annual serving beverage industries of its product, and approximately 3,500,000,000 of canned food industries, inhalator jar yearly productive capacity reaches 9.5 hundred million, 60,000,000 of steel drum year production and processing amounts.Approximately more than 250 hundred million yuans of current national packaging container of metal total industrial output values, mental package industry is keeping more stable, healthy, lasting growth momentum, the basic increasing velocity that keeps year 7% left and right.
The thin-walled package container that packaging container of metal is normally manufactured with sheet metal, in its process of manufacture, mostly need welding, China's food can body welding is at present mainly to adopt resistance melting welding, exists the joint form that power consumption is large, heat affected area is large, applicable and can weld the problems such as thickness of workpiece is restricted.Tinplate, through melting resistance postwelding, due to the impact of welding high temperature, can form a sheet iron strip that there is no protective coating and coating on inside and outside wall, and this sheet iron strip meeting oxidation by air blackening, is also very easily subject to the corrosion of tank content.In order to improve the corrosion resistance of welding position, after welding, must spray nitrogen (High Purity Nitrogen) processing by butt welded seam, and carry out weld seam coating.Will cause face of weld injustice if welding quality is not high, make coating technique be difficult to control, form the coating defects such as sand holes or bubble, occur that weld seam gets rusty or the problem such as seepage just unavoidably thus.
In addition, when melting welding, electric current is excessive, easily produces burr, and as coating layer can not cover burr completely, cause therefrom the perforation of burr periphery burn into, leak, and electric current is too small, easily causes not prison welding or does not weld, i.e. rosin joint, thus cause leakage.
Find also to exist hard-to-weld chrome-plated metal light sheet material through investigation, its advantage is that metal substrate is thin, it is low to be used for tank cost processed, pollute few, but layer is chrome-plated material, cannot realize welding procedure with traditional electric resistance welding, urgent need will find a kind of welding method, opens up the application market of wide chrome-plated metal plate.
Laser welding technology can effectively address these problems, and be tending towards ripe abroad, and China is in this regard also in the exploratory stage at the laser processing technology of small-sized thin-wall metal packing container (as built-up tin).The laser welding system of China mainly depends on import, and welding procedure is also immature.Foreign Laser welding system supplier likely provides certain a set of specific technological parameter, and still, because steel plate wall thickness, composition and coated metal that tank processed adopts etc. can change to some extent, thereby the technological parameter that systems provider provides can not use mostly.Restrict like this, widely the application of laser welding process in packaging container of metal is manufactured.So, must study technological parameter, plate thickness, composition and the coated metal rule that affects on packaging container of metal laser weld, for packaging container of metal material is formulated suitable laser welding process, realize preliminary election and the optimization of laser welding process parameter, reduce the number of times of engineer testing, judge welding condition deep penetration welding penetration stability, prevent weld defect, ensure that food sanitation safe is all of great significance.
Summary of the invention
In order to overcome the deficiencies in the prior art, the invention provides a kind of welding quality high, save power consumption, reduce production costs, can weld the laser welding process for thin-wall tinplate packaging material of chromium plating tinplate thin-walled.
The technical solution adopted for the present invention to solve the technical problems is:
A kind of laser welding process for thin-wall tinplate packaging material, chromium plating tinplate and the zinc-plated tinplate of applicable welding 0.20mm-0.27mm, adopt laser welding process to weld the tinplate of above-mentioned thickness, and required laser performance parameter is as follows:
Laser power 1.5-1.9kw;
Frequency 20.0Hz;
Simple venation energy 3.92-4.78J;
Pulsewidth 2.3-2.7ms;
Speed of welding 5.0mm/s;
Pad spacing is 0.2mm;
Defocusing amount 2.0-3.0mm.
Common are as the tinplate of packaging material: the thick chromium plating tinplate of 0.20mm, the thick chromium plating tinplate of 0.23mm, the thick chromium plating tinplate of 0.27mm, the thick zinc-plated tinplate of 0.20mm, the thick zinc-plated tinplate of 0.23mm mm and the thick zinc-plated tinplate of 0.27mm, the welding parameter of these six kinds of materials is as following table:
The invention has the beneficial effects as follows:
The present invention is by the selection of laser parameter, chromium plating tinplate to 0.20mm-0.27mm and the welding of zinc-plated tinplate are realized, smooth welding joint is attractive in appearance, can avoid metal can distortion, inside and outside wall coating impaired, weld seam and mother metal fuse into one, weld seam striped is fish scale-shaped and is evenly distributed, flawless, pore etc. be weld defect obviously, be conducive to avoid the breakage of packaging container of metal, the leakage of content, reduce enterprise and client's loss, high-quality welding can prevent the putrid and deteriorated of content effectively, and guarantee eater's is healthy.
Adopt laser weld substitutional resistance Welding to improve welding quality, although the electric light power conversion gross efficiency of laser instrument only has 10%, but because hot spot is little, power density is large, the little order of magnitude of energy Ratios traditional welding that laser weld is required, thereby day-to-day operation expense is high unlike traditional welding, save power consumption, reduce production costs, also solved the hard-to-weld problem of chrome-plated metal plate, because laser weld does not generally add filling metal, free from environmental pollution have a good social benefit.
Detailed description of the invention
A kind of laser welding process for thin-wall tinplate packaging material, is applicable to chromium plating tinplate and the zinc-plated tinplate of welding 0.20mm-0.27mm, adopts laser welding process to weld the required laser parameter of the tinplate of above-mentioned thickness as follows:
Laser power 1.5-1.9kw;
Frequency 20.0Hz;
Simple venation energy 3.92-4.78J;
Pulsewidth 2.3-2.7ms;
Speed of welding 5.0mm/s;
Pad spacing is 0.2mm;
Defocusing amount 2.0-3.0mm.
Select the laser instrument within the scope of above-mentioned parameter, all can complete chromium plating tinplate to 0.20mm-0.27mm and the welding of zinc-plated tinplate.
Adopt laser weld substitutional resistance Welding to improve welding quality, although the electric light power conversion gross efficiency of laser instrument only has 10%, but because hot spot is little, power density is large, the little order of magnitude of energy Ratios traditional welding that laser weld is required, thereby day-to-day operation expense is high unlike traditional welding, save power consumption, reduce production costs, also solved the hard-to-weld problem of chrome-plated metal plate, because laser weld does not generally add filling metal, free from environmental pollution have a good social benefit.
The present invention, by a large amount of experiments, draws above-mentioned parameter area, and equipment and the method in experiment, used are as follows: first, according to consulting related data and great many of experiments, tentatively determine the process parameters range of laser weld; By changing the various parameters of laser weld, study the impact of single factors vary on laser weld result, the detection of the quality analysis of butt welded seam surface topography and weld strength obtains the optimal processing parameter combination of the chromium plating of laser weld different-thickness and zinc-plated tinplate packaging sheet metal.
One, experiment relevant device
(1) laser welding apparatus
PB300 laser-beam welding machine, Feedback of Power optical fibre transmission laser-beam welding machine, Dazu Laser Science & Tech Co Ltd, Shenzhen City produces.The performance parameter of bonding machine is as following table:
Model |
?PB300 |
Optical maser wavelength |
?1064nm |
Maximum laser power output |
?300W |
Maximum laser pulse energy |
?50J/10ms |
Pulse width |
?0.1-50ms |
Pulse frequency |
?1-200Hz |
Electricity needs |
?380V/50Hz/30A |
Aim at location |
Ruddiness shows, CCD surveillance |
(2) laser cutting machine CS035F-50X, cutting parameter is: electric current 150A, pulsewidth 0.4ms, frequency 120Hz, speed 6m/s-8m/s, steel plate aperture time 500ms, Dazu Laser Science & Tech Co Ltd, Shenzhen City produces.
(3) electronic universal cupping machine, Shenzhen Sans Material Detection Co., Ltd produces.
(4) equipment of processing sample: wire cutting machine tool and stamping machine.
Two, test material
The test material that the present invention selects, for application coating tinplate metal packing material more widely, is produced by Zhongyue Tin-Plate Co., Ltd., Zhongshan.
Chromium plating tinplate, thickness 0.20mm, 0.23mm and 0.27mm.
Zinc-plated tinplate, thickness 0.20mm, 0.23mm and 0.27mm.
Three, laser welding process
Laser weld is had relatively high expectations to welding joint-cutting, and namely the edge neat of weldment will be got well.Carry out sample pretreating in early stage therefore use laser cutting.Simultaneously, because experimental situation humiture changes, before welding, there is oxidative phenomena in portions cut, so use sand paper to carry out the part processing of derusting.Because specimen size, the particularity of shape, in the time of welding, need to be fixed by fixture, ensures that in welding process, two sheet metals are concordant.Adopt laser cutting machine every kind of thickness coated metal thin plate to be processed into 30 of the test specimens of 100mm × 60mm, carry out along its length laser butt welding test (totally 60 welded specimens).
According to forefathers' research experience, laser apparatus condition and great many of experiments, initial option welding parameter is: (1) laser peak power: be one of parameter of most critical in Laser Processing.Adopt higher power density, in delicate time range, top layer can be heated to boiling point, produces vaporization in a large number.Therefore, high power density is favourable for materials processing.
(2) laser pulse width: laser waveform is an important index in the miniature welding of pulse.Because in the time that laser incides metal surface, metal surface will lose the laser energy reflection of 60%-98%, adopts suitable laser waveform can reduce the loss of this part energy.
(3) single pulse energy 3.6-6.0J.
(4) speed of welding 4.0-6.0mm/s.
(5) defocusing amount 2.0-4.0mm.
(6) pad spacing is 0.2mm.
(7) go out light frequency 20.0Hz.
Four, welded specimen quality testing
(1) laser butt welding welded seam quality testing
Adopt PB300 laser-beam welding machine and CCD surveillance monitoring welding process, and detect weld width and face of weld quality.The test item of laser butt welding is mainly that the presentation quality of welded seam is detected.Observe the penetration of welded seam, and the surface quality of welded seam is carried out to double check, judged whether obvious pore, crackle, burn through, the weld defects such as limit that collapse, measure weld width, comprehensively pass judgment on welding effect.
(2) tensile strength performance detects
According to GB GB/T228--2002, adopt mechanical property and the crack conditions of electronic universal cupping machine to sample to analyze.
In order to judge welding point tissue changes whether the mechanical property of banjo fixing butt jointing has been produced to impact, and experiment has detected sample hot strength and percentage elongation according to national standard.Result shows: in tension test, butt welding sample fracture position is positioned on mother metal, and this explanation welding point resistance to deformation is under external force suitable with mother metal with damage capability.Therefore laser weld weld strength is high, not cracky, leakage in storage and transport process.
By experiment, draw, the optimal parameter of the thick chromium plating tinplate of 0.20mm, the thick chromium plating tinplate of 0.23mm, the thick chromium plating tinplate of 0.27mm, the thick zinc-plated tinplate of 0.20mm, the thick zinc-plated tinplate of 0.23mm mm and the thick zinc-plated tinplate sheet laser soldering apparatus of 0.27mm is as following table:
Laser weld weld seam and the mother metal of above-mentioned parameter fuse into one, and smooth welding joint is attractive in appearance, and weld seam striped is fish scale-shaped and is evenly distributed, and flawless, pore etc. are weld defect obviously, and metal can not be out of shape, inside and outside wall coating can be not impaired yet.
Laser power is less than 1.5kw, and simple venation energy is less than 3.92J, and pulsewidth is less than 2.3ms, and defocusing amount is greater than 3.0mm, metal can not penetration, and weld seam is insecure, and laser power is greater than 1.9kw, and simple venation energy is greater than 4.78J, pulsewidth is greater than 2.7ms, and defocusing amount is less than 2.0mm, there will be and steps on limit, metal can distortion.
To same thickness thin-walled metal material, increase pulsewidth, required thermal power density is low, and laser parameter can weld wide ranges; For different-thickness thin-wall metal material, increase laser power, single pulse energy, pulsewidth or the speed of welding that reduces, defocusing amount can make fusion penetration increase; Increase laser power, single pulse energy, pulsewidth, defocusing amount or the speed of welding that reduces and can make molten wide broadening.Speed of welding size on the fish scale-shaped striped pattern impact of welded seam surface significantly.