CN105603418B

CN105603418B - The method for improving 42CrMo steel microhardnesses in laser melting coating using cladding powder

Info

Publication number: CN105603418B
Application number: CN201610044447.8A
Authority: CN
Inventors: 罗震; 谈辉; 颜福裕; 姚杞
Original assignee: 天津大学
Priority date: 2013-08-01
Filing date: 2013-08-01
Publication date: 2018-02-06
Also published as: CN104131281A; CN105603418A; CN104131281B

Abstract

The present invention discloses the method that 42CrMo steel microhardnesses are improved in laser melting coating using cladding powder, and cladding powder is made up of following component by weight percent, and Cr is that 20~22%, Ni is that 10~11%, Al is 9.5~10.5%, CeO₂It is surplus for 1~1.5%, Fe, after the powder prepared is mixed into pasty state or paste by alcohol, coated in 42CrMo steel surfaces, composite coating can be obtained by laser melting coating after drying.Technical solution of the present invention can obtain the laser cladding layer of flawless, and hardness is higher, wearability is preferable, and price is relatively low, is not only suitable for laboratory research, is also suitable for less demanding production and processing.

Description

The method for improving 42CrMo steel microhardnesses in laser melting coating using cladding powder

The present patent application is the divisional application of parent application " simple iron based laser cladding powder and cladding layer preparation method ", The Application No. 2013103355538 of parent application, applying date of parent application are August in 2013 1 day.

Technical field

The present invention relates to laser cladding of material field, more particularly, is related to a kind of easy iron based laser cladding powder Powder material and cladding layer preparation method.

Background technology

Laser melting and coating technique is the important component in Laser Surface Modification Technology, due to that can significantly improve material Wearability, corrosion resistance, heat resistance and some electric properties, are rapidly developed in production application.It is but currently employed On the one hand laser cladding powder is to continue to use the Ni-based of thermal spraying material, iron-based, cobalt-based self-fluxing alloyed powder；On the other hand it is exactly The ceramic materials such as WC, TiC, SiC are added in alloy powder to improve the hardness of cladding layer and wearability, but its crack sensitivity Also can increase.Therefore, laser cladding powder of the research with combination properties such as excellent abrasive resistance, corrosion resistance and heat resistances, is used for The reparation of machine components damageable zone, wear-resisting, anticorrosion layer is obtained, the service life of machinery equipment can be greatly prolonged, not only may be used To improve production efficiency, additionally it is possible to overcome the workpiece of the generally existing in the conventional surface treatment technology such as built-up welding, thermal spraying to deform The problem of big and bond strength is low, has huge development potentiality.Because heat input is relatively low, workpiece deformation is small, crystal grain is tiny And intensity, the advantages that hardness is high, and the wearability of material, corrosion resistance, heat resistance can be significantly improved and some are electric Performance, it is rapidly developed in production application.But currently employed laser cladding powder be on the one hand continue to use containing boron and The self-fluxing alloy powder used for hot spraying of silicon, its be disadvantageous in that in most self-fluxing alloy powders the content of boron and silicon compared with Height, because cooling velocity is fast in laser cladding process so that some are mingled with borosilicate such as can not be smoothly molten from what is quickly solidified Emersion in pond, cause laser cladding layer cracking sensitivity larger；On the other hand it is exactly using the tailored flour containing three or four kinds of elements End, it is not easy to obtain good combination property.

The content of the invention

It is an object of the invention to overcome the deficiencies in the prior art, for existing laser cladding powder powder material be improved with Solves above-mentioned technical problem.

The technical purpose of the present invention is achieved by following technical proposals：

Simple iron based laser cladding dusty material, according to mass percent (i.e. each component sum is 100%) by following Component forms：Cr is that 20~22%, Ni is that 10~11%, Al is 9.5~10.5%, CeO₂It is surplus for 1~1.5%, Fe.

It is preferably as follows component and content：Cr is that 21~22%, Ni is that 10~11%, Al is 10~10.5%, CeO₂For 1~ 1.2%, Fe are surplus.

It is the powder that purity is more than or equal to 99% from each component in above-mentioned simple iron based laser cladding powder, Particle diameter is 100-500 mesh, preferably 200-300 mesh, i.e. chromium powder, nickel powder, aluminium powder, ceria, iron powder.

In the inventive solutions, Cr and Ni is main alloying element, and wherein Cr is mainly used in improving quenching degree, Solution strengthening is produced, promotes M formation, in the design of High-alloy Ultra-high Strength Steel, Cr, which has, promotes (the substitution of post-curing effect Mo₂Mo in C forms (Mo, Cr)₂C), the precipitated phase of small and dispersed is formed, improves hardness and tensile yield strength；Ni is then main For improving wetability and improving cladding layer capability.The Al of addition is mainly used in replacement B and Si and carrys out deoxidation, can also improve alloy High-temp plastic, the shrinkage factor of cladding layer is reduced, it is hereby achieved that the cladding layer without crackle.In addition, add a certain amount of CeO₂, on the one hand crystal boundary can be purified, further reduce the content of its objectionable impurities；On the other hand, rare earth is made in itself For a kind of active material, grain boundary interfaces tension force can be reduced, so as to reduce the driving force that crystal grain is grown up, it is suppressed that what crystal grain was grown up Tendency, meanwhile, the rare earth compound of formation can also be used as forming core core in one time of crystallization, increase forming core number, from And crystal grain thinning, improve the hardness and wearability of cladding layer.

When being prepared, after the quality of each component of precise, be sufficiently mixed with uniformly, such as After the powder that various elements are weighed using electronic scale, in mortar mechanical lapping half an hour make it well mixed.

In being welded using the simple iron based laser cladding power applications of the present invention to laser melting coating, simple iron based laser is melted Behind whiting end and ethanol mixing, substrate material surface is coated uniformly on, cladding layer can be obtained by laser melting coating after air-drying.

The pure absolute ethyl alcohol of wherein described ethanol Analysis about Selection；In simple iron based laser cladding powder and alcohol mixture In, it is made up of according to mass percent 92~95% simple laser cladding powder and 5~8% ethanol.

After simple iron based laser cladding powder and ethanol mixing, pasty state or paste are formed, in order in matrix material table Face is coated, and forms preformed layer after coated, the preformed layer thickness is 1-2mm.

It is 42CrMo steel from matrix material when carrying out laser melting coating, Optimizing Process Parameters are：Laser power is 1550 ~1650KW, spot diameter are 0.8-1mm, and sweep speed is 150-200mm/min, defocusing amount 0, and protective gas uses argon Gas, nitrogen or helium, gas flow are 20-25L/min；It is preferred that laser power is 1580~1620KW, spot diameter is 0.8-1mm, sweep speed are 180-200mm/min, defocusing amount 0, and protective gas uses argon gas, gas flow is 22- 25L/min。

Compared with prior art, the invention has the advantages that：

(1) proposition of the invention substitutes B and Si come deoxidation by Al addition, can also reduce cladding layer Shrinkage factor, it is hereby achieved that the cladding layer without crackle.

(2) present invention in laser cladding powder by adding suitable rare earth element ce O₂, can be with crystal grain thinning, significantly Improve the hardness and wearability of cladding layer.

(3) present invention can add one as a kind of easy iron based laser cladding dusty material according to being actually needed The member such as fixed Co, Mo, Ti usually further improves cladding layer capability.

Embodiment

Technical scheme is further illustrated with reference to specific embodiment, wherein using each medicine such as following table institute Show.

Nomenclature of drug Molecular formula Purity Specification Manufacturer Iron powder Fe >=99% Analyze pure The factory of Tianjin chemical reagent one Chromium powder Cr >=99% Analyze pure Tianjin recovery fine chemistry industry research institute Nickel powder Ni >=99.5% Analyze pure The factory of Hubei Tianmen chemical reagent two Aluminium powder Al >=99% Analyze pure Tianjin Feng Chuan chemical reagent Co., Ltd Ceria CeO₂ >=99.5% Analyze pure Shanghai crystalline substance pure reagent Co., Ltd

The chemical analysis of the matrix material 42CrMo steel used is as shown in the table

C Mn Si Cr Mo Ni Cu 0.38~0.45 0.50~0.80 0.17~0.37 0.90~1.20 0.15~0.25 ≤0.030 ≤0.030

The weight/mass percentage composition of each component shown in foundation following table, the powder (200 of various elements is weighed using electronic scale Mesh), mortar is poured into, grinding half an hour in mortar makes it well mixed, obtains iron based laser cladding dusty material.

Numbering Cr Ni Al CeO₂ Fe Embodiment 1 20% 10% 10% 1% Surplus Embodiment 2 20% 10% 10% 1.5% Surplus Embodiment 3 21..2% 10.8% 9.8% 1.5% Surplus Embodiment 4 22% 10.5% 10.2% 1.2% Surplus Embodiment 5 20.5% 10.2% 10.5% 1% Surplus Embodiment 6 20.5% 10.6% 9.5% 1.3% Surplus Embodiment 7 21% 11% 9.5% 1% Surplus Embodiment 8 21.5% 11% 10.5% 1.4% Surplus

After embodiment 1-8 in above table is mixed respectively obtained iron based laser cladding dusty material with it is analytically pure Absolute ethyl alcohol is carried out after being well mixed, and coated in substrate material surface, cladding layer can be obtained by laser melting coating after air-drying, point Laser melting coating is not carried out according to following four groups of techniques, laser uses JK2003SM types Nd：YAG.

First group, simple iron based laser cladding powder 92wt%, ethanol 8wt%, preformed layer thickness is 2mm, laser power Nitrogen, gas stream are used for 1650KW, spot diameter 1mm, sweep speed 200mm/min, defocusing amount 0, protective gas Measure 25L/min.

Second group, simple iron based laser cladding powder 95wt%, ethanol 5wt%, preformed layer thickness is 1mm, laser power Argon gas, gas are used for 1550KW, spot diameter 0.8mm, sweep speed 150mm/min, defocusing amount 0, protective gas Flow 20L/min.

3rd group, simple iron based laser cladding powder 93wt%, ethanol 7wt%, preformed layer thickness is 1.5mm, laser work( Rate is 1580KW, spot diameter 0.8mm, sweep speed 180mm/min, defocusing amount 0, and protective gas uses helium, gas Body flow 22L/min.

4th group, simple iron based laser cladding powder 94wt%, ethanol 6wt%, preformed layer thickness is 1mm, laser power Argon gas, gas stream are used for 1620KW, spot diameter 1mm, sweep speed 150mm/min, defocusing amount 0, protective gas Measure 25L/min.

Detected using EMS-2003+ intelligence Magnetic Memory/vortex/precursor in far field instrument after laser melting coating, do not had It was found that crackle.Sample prepared by every group of technique carries out property test, and takes the average value of 8 embodiments, as every group of technique Comparison other.

The microhardness of cladding layer is measured using automatic turret digital display sclerometer, the experimental results are shown inthe following table

Hardness number 1 Hardness number 2 Hardness number 3 Hardness number 4 Average hardness Mother metal 286HV 282HV 285HV 284HV 284HV Cladding layer 852HV 861HV 882HV 870HV 866HV

Using MM-200 type determination of wear testing machine, its wearability, specimen size are 7 × 7 × 25mm, and friction duty is Dry grinding sliding friction, is loaded as 5kg, rotating speed 200r/min, experimental period 1h.And measure front and rear quality with electronic scale and (survey Cleaned before amount with ultrasonic washing instrument), the experimental results are shown inthe following table

First group Quality/g before abrasion Quality/g after abrasion Weightlessness/mg Mother metal 9.0479 9.0008 47.1 Cladding layer 9.5480 9.54345 4.55

Second group Quality/g before abrasion Quality/g after abrasion Weightlessness/mg Mother metal 9.0479 9.0008 47.1 Cladding layer 9.7521 9.7475 4.6

3rd group Quality/g before abrasion Quality/g after abrasion Weightlessness/mg Mother metal 9.0479 9.0008 47.1 Cladding layer 9.5480 9.5432 4.8

4th group Quality/g before abrasion Quality/g after abrasion Weightlessness/mg Mother metal 9.0479 9.0008 47.1 Cladding layer 9.5480 9.5438 4.2

It can be seen that microhardness and wear-resisting can be effectively improved after laser melting coating using the iron based laser cladding powder of the present invention Performance.

Exemplary description has been done to the present invention above, it should explanation, in the situation for the core for not departing from the present invention Under, any simple deformation, modification or other skilled in the art can not spend the equivalent substitution of creative work equal Fall into protection scope of the present invention.

Claims

1. the method that 42CrMo steel microhardnesses are improved in laser melting coating using cladding powder, it is characterised in that by cladding powder Behind end and ethanol mixing, matrix material 42CrMo steel surfaces are coated uniformly on, cladding can be obtained by laser melting coating after air-drying Layer；In cladding powder and alcohol mixture, according to mass percent by 92~95% cladding powder and 5~8% ethanol Composition, cladding powder are made up of according to mass percent following components：Cr be 20~22%, Ni be 10~11%, Al be 9.5~ 10.5%, CeO₂It is surplus for 1~1.5%, Fe；When carrying out laser melting coating, technological parameter is：Laser power be 1550~ 1650kW, spot diameter are 0.8-1mm, and sweep speed is 150-200mm/min, defocusing amount 0, and protective gas uses argon Gas, nitrogen or helium, gas flow are 20-25L/min；From each component it is that purity is more than or equal in cladding powder 99% powder, particle diameter are 100-500 mesh, the pure absolute ethyl alcohol of the ethanol Analysis about Selection.

2. the method according to claim 1 for improving 42CrMo steel microhardnesses in laser melting coating using cladding powder, Characterized in that, cladding powder is following component and content：Cr is that 21~22%, Ni is that 10~11%, Al is 10~10.5%, CeO₂It is surplus for 1~1.2%, Fe.

3. the method according to claim 1 for improving 42CrMo steel microhardnesses in laser melting coating using cladding powder, Characterized in that, cladding powder diameter is 200-300 mesh.

4. the method according to claim 1 for improving 42CrMo steel microhardnesses in laser melting coating using cladding powder, Characterized in that, after cladding powder and ethanol mixing, pasty state or paste are formed, in order to be applied in substrate material surface Cover, form preformed layer after coated, the preformed layer thickness is 1-2mm.

5. the method according to claim 1 for improving 42CrMo steel microhardnesses in laser melting coating using cladding powder, Characterized in that, when carrying out laser melting coating, technological parameter is：Laser power is 1580~1620kW, spot diameter is 0.8- 1mm, sweep speed are 180-200mm/min, defocusing amount 0, and protective gas uses argon gas, and gas flow is 22-25L/ min。