Test Study Of 35CrMo Steel By Laser Cladding For The Advanced Remanufacturing

Laser cladding is widely used in the field of remanufacturing because of it's small deformation,high bonding strength,environmental,protection,high efficiency,no harsh environmental requirements as a new surface manufacturing technique.The quality of the cladding coating is concerned with the service life after remanufacturing,and it's macroscopic morphology,dimensional accuracy and physical properties has a closer relation with it's geometric features on the cross section.Therefore,it is very important to research the geometric features and properties of cladding layer.In this paper,the single-pass and double-pass laser cladding the 354 iron-based powder on 35CrMo steel surface with the range of suitable process parameters(defocusing amount scanning speed,laser power).Seeing the cross section morphology under the different parameters on the microscope,and measure it's height,width and depth of molten pool.And research the quality and properties of the coating.The specific research work are as follows:(1)Analysis of the geometry and properties of the cladding layer under the process parameters influence at a certain speed of delivery.It is found that width of cladding layer increases with from larger with the amount of central point,with the increase of scanning speed,the cladding layer height,width and depth of molten pool is a trend of decline,with the increase of laser power,cladding layer width,height and depth of molten pool increases accordingly.When the process parameters are 2.5kW of laser power,20mm away from central point,and 6mm/s of scanning speed,the dilution rate is close to 10%,which is in line with the production requirement,and the most regular coating shape is obtained.(2)Through the microstructure and hardness of the samples were observed and compared,it is found that the hardness of the cladding layer decreases with the increase of the surface,and the transverse hardness value changes little.When the dilution approach is close to 10%,the bonding of the cladding layer is close and orderly,the grain size is small,and the hardness of the cladding layer is the largest.Under the same process parameters,the hardness of double-pass cladding zone is lower than that of single-pass cladding layer.(3)Based on experimental study(1),(2),in the preferred choice of process parameters base powder 3540 we added mass fraction is 5%,10%,15%,20%of TiB2 powder to strengthen the wear resistance properties of cladding layer and analyzing the influences of different percentage of TiB2 content on properties of cladding layer.The results showed while adding amount is 10%TiB2,the cladding layer had better surface properties,and can obtain better friction and wear properties.In this paper,based on the research between of the geometrical features and process parameters of cladding layer,control the geometric shape of cladding layer and achieve the rapid process planning of laser cladding.Researching the geometrical features of cladding and it's quality and property has great significance for improve mechanical properties of coating.