CN202543329U

CN202543329U - Composite surfacing coating structure for repairing metal workpieces with bad weldability

Info

Publication number: CN202543329U
Application number: CN 201220031666
Authority: CN
Inventors: 李胜; 韩立发; 张小萍; 谢春晓
Original assignee: Dongguan University of Technology
Current assignee: Dongguan University of Technology
Priority date: 2012-02-01
Filing date: 2012-02-01
Publication date: 2012-11-21
Anticipated expiration: 2022-02-01

Abstract

The utility model discloses a composite surfacing coating structure for repairing metal workpieces with bad weldability. The composite surfacing coating structure comprises a good-plastic toughness middle coating which is deposited on the surface of a workpiece by using a micro arc spark deposition technology and an external coating which is rapidly prepared on the middle coating by using a laser cladding method. By using a 'laser cladding-micro arc spark deposition composite restoration technology', the laser cladding technology and the micro arc spark deposition technology are combined and the advantages and disadvantages thereof are fully utilized, so that the coatings do not crack when restoration is carried out on the workpieces with bad weldability, the tissues and properties of the surfaces of the restored workpieces are basically not changed and the restoration speed is faster.

Description

A kind of composite overlaying coating structure that is used to repair the metal works of weldability difference

Technical field

The utility model relates to a kind of composite overlaying coating structure that is used to repair the metal works of weldability difference.

Background technology

Compare with conventional surface coating technologies such as plating with flame spray welding, laser melting coating (also claiming the laser built-up welding) technology has cladding layer and advantage such as matrix bond is firm, thinning ratio is low, thermal distortion is little, in actual production, has obtained application to a certain degree.But there is big problem in laser melting and coating technique as recovery technique, on the workpiece of weldability differences such as high-carbon alloy steel, cast iron and non-ferrous metal, carries out being easy to generate when cladding is repaired crackle exactly.Workpiece surface certainly led to the fusion area of certain depth (about 0.05-0.25 mm) when the major cause that cracks was laser melting coating; The fusion area exists tensile stress, and meanwhile, the workpiece plasticity and toughness of weldability difference are poor; Tensile stress can not get discharging; Just cause cracking easily, the fusion area degree of depth is big more, and the crackle tendency is big more.Some stakeholders adopt the method for laser melting coating tie coat to solve the crack problem on the workpiece of weldability difference; The first good laser cladding layer of preparation one deck plasticity and toughness on workpiece just, the needed laser cladding layer of refabrication workpiece surface (in most cases being the cladding layer of high firmness or higher hardness) above that then.Although the laser melting coating transition layer that plasticity and toughness are good can reduce the coating overall stress; And then minimizing cladding layer tearing tendency; But because laser melting coating, workpiece surface must have the fusion area of certain depth, otherwise cladding layer and workpiece bonding strength are low excessively; Cladding layer peels off easily, and workpiece surface still exists certain tensile stress and the tearing tendency that therefore causes like this.Therefore, adopt the method for laser melting coating tie coat not have thoroughly to solve laser cladding layer on the workpiece of the welding property difference problem that ftractures.In addition; Although the relative conventional stack welding technology of laser melting and coating technique is few to the hot input of workpiece substrate; But the degree of depth of laser melting and coating technique heat affected zone (generally speaking; The degree of depth of heat affected zone is no less than 0.25 mm) still very important, this can cause workpiece surface to produce the tissue variation, and this variation tends to deleterious impact for the workpiece of welding property difference.The heavily stressed position of big load is born on the surface that resembles roll and precision die like this, organizes variation can cause the weakening of its supporting capacity and life-span to be reduced, and often can bring out workpiece surface simultaneously and germinate crackle in the course of the work, reduces the workpiece performance.

Micro-arc spark deposition (also claiming electric spark deposition) technology has the following advantage: repair layer or strengthening layer and workpiece substrate are the high metallurgical binding of bonding strength; The workpiece surface melting area and the heat affected zone degree of depth very little (about 0.01 mm of the fusion area degree of depth, about 0.02 mm of the heat affected zone degree of depth); Cost of equipment is low, and structure is comparatively simple, and is in light weight, easy to carry, uses flexible etc.The micro-arc spark deposition technique has been successfully applied to the reparation of parts such as cutter and mould; But greatest problem that should technology is that the coating sedimentation velocity is slow; For the coat-thickness that needs built-up welding to repair big (coat-thickness＞0.35 mm); Especially for repairing this situation than big area and the bigger part of coat-thickness, generally speaking the micro-arc spark deposition technique is unaccommodated.Under many circumstances; The reparation of waste and old part at first need be passed through wearing and tearing, corrosion and fatigue and the crackle layer that mechanical workout is removed the surface; The built-up welding thickening is repaired then; Surplus to part original size and surfaceness are removed in reprocessing at last, and built-up welding reparation amount is not very little, so this deficiency has greatly limited this The Application of Technology.

Summary of the invention

The technical problem that the utility model will solve provides the composite overlaying coating structure that the metal works of weldability difference is repaired in a kind of simple in structure being used to.

For solving the problems of the technologies described above; The utility model adopts following technical scheme: comprise and adopt the micro-arc spark deposition technique on workpiece surface, to deposit the good inter coat of one deck plasticity and toughness, and on inter coat, adopt the exterior coating of the quick preparation of method of laser melting coating.

Further, the thickness of said inter coat is 0.05-0.35 mm.

Being used to of the utility model repaired the composite overlaying coating structure of the metal works of weldability difference; Owing to adopt " laser melting coating-micro-arc spark deposits compound recovery technique "; Laser melting and coating technique and micro-arc spark deposition technique are combined, make full use of relative merits separately, reached that coating can not ftracture when on the workpiece of weldability difference, repairing; Basically do not change the tissue and the performance of repairing workpiece surface, reparation speed is purpose faster again.

Description of drawings

Fig. 1 is used to repair the synoptic diagram of composite overlaying coating structure of the metal works of weldability difference for the utility model.

Embodiment

In the present embodiment; With reference to shown in Figure 1; This is used to repair the composite overlaying coating structure of the metal works of weldability difference; Comprise and adopt the micro-arc spark deposition technique on workpiece surface 2, to deposit the good inter coat 1 of one deck plasticity and toughness, and on inter coat 1, adopt the exterior coating 3 of the quick preparation of method of laser melting coating.Wherein, the thickness of said inter coat 1 is 0.05-0.35 mm.The micro-arc spark deposition technique can avoid workpiece surface 2 to produce bigger melting area and heat affected zone; Prevent that the workpiece surface repair layer from cracking; Basically do not change the tissue and the performance of repairing workpiece surface; The inter coat that plasticity and toughness are good plays the purpose of slowing down the compound coating stress concentration simultaneously, and laser melting and coating technique plays a part quick reparation.Like this, just can give full play to laser melting and coating technique and micro-arc spark deposition technique advantage separately, avoid deficiency separately, thereby reach perfect purpose of repairing the workpiece of weldability difference.

Wherein, The advantage of laser melting and coating technique is to repair rapid speed, and shortcoming is the fusion area degree of depth relatively large (about 0.05-0.25 mm), and the fusion area tensile stress is relatively large; Thereby on the workpiece of weldability difference, repair and be easy to generate crackle; In addition, the heat affected zone degree of depth (generally being no less than 0.25 mm) is bigger, possibly reduce the workpiece surface performance.The advantage of micro-arc spark deposition technique is the fusion area degree of depth very little (about 0.01 mm); The fusion area tensile stress is very little; On the workpiece of weldability difference, adopt the good electrode materials reparation of plasticity and toughness to be difficult for cracking; (about 0.02 mm) is also very little for the heat affected zone degree of depth, can not change the tissue and the performance of repairing workpiece surface basically, and shortcoming is that reparation speed is slow.The present invention; I.e. " laser melting coating-micro-arc spark deposits compound recovery technique "; Laser melting and coating technique and micro-arc spark deposition technique are combined, make full use of relative merits separately, reached that coating can not ftracture when on the workpiece of weldability difference, repairing; Basically do not change the tissue and the performance of repairing workpiece surface, reparation speed is purpose faster again.

Below the utility model is done a detailed description; The above is merely the preferred embodiment of the utility model, when not limiting the utility model practical range; Be allly to do impartial change and modify, all should still belong in the utility model covering scope according to the application's scope.

Claims

1. composite overlaying coating structure that is used to repair the metal works of weldability difference; It is characterized in that: comprise and adopt the micro-arc spark deposition technique on workpiece surface, to deposit the good inter coat of one deck plasticity and toughness, and on inter coat, adopt the exterior coating of the quick preparation of method of laser melting coating.

2. the composite overlaying coating structure that is used to repair the metal works of weldability difference according to claim 1, it is characterized in that: the thickness of said inter coat is 0.05-0.35 mm.