Research On Laser Cladding For High Acid Value Crude Oil Processing Plant

In recent years,oil refining industry,high acid value trend of crude oil is obvious,naphthenic acid corrosion of the equipment is becoming increasingly serious,making technical measures to be taken in the processing of high-acid crude oil particularly important,which also has great significance to the producing safety of refining enterprise's equipment and reducing crude oil procurement costs.The current widely used method is to select the appropriate high-performance alloy materials to control the corrosion.However,the high cost of materials greatly increases the cost of construction and renovation of refineries.The traditional cladding process can not be large-scale applied due to unstable forming,low cladding efficiency,large dilution rate,large labor intensity,poor metallurgical bonding and other factors.In order to solve this problem,this paper proposes to use an advanced laser cladding technology to low erosion resisting metal materials surface to make surface improvement,thus improving the getting worse situation of naphthenic acid corrosion of the oil refining equipment caused by the rising acid value of crude oil.The following studies were conducted:First of all,according to the experimental requirements,a laser cladding experimental platform was set up.The substrate material used in the experiment,clad powder and corrosion solution was determined according to the experimental purposes.Up to three groups of Inconel 625 alloy powder laser single channel cladding experimental schemes with single factor process parameters are designed.The analysis method of cladding layer forming quality which affected by different process parameters is described,and the detecting method to the cladding layer's organization and properties is clarified.The experimental cladding scheme of Inconel 625 alloy powder with single layer and multichannel lap laser was designed.Secondly,compared with the experimental results of Inconel 625 laser cladding under different single process parameters,this paper analyzed that the appearance,macro-size,dilution rate and infiltration angle of the cladding layer forming features were determined by the defocusing amount,power and scanning speed and other parameters according to theoretical basis,as well as their corresponding relationships.Finally,Inconel 625 laser single channel cladding layer with high melting depth,low dilution rate,large infiltration angle and good metallurgical bonding is obtained through the study of the heat source control mechanism of semiconductor laser and the quality control of cladding.Finally,the obtained Inconel 625 laser cladding layer was subjected to organizational analysis and performance test.The results showed that the hardness of the material surface was significantly improved,and a good metallurgical bonding between the cladding layer and the substrate metal was realized.The organizations are successively flat crystal,coarse dendrites and small dendrites,from the bonding surface to the cladding layer top.The main phase is?-Ni.The iron element in substrate material diffused to the cladding layer alloy through dilution phenomenon.High temperature resisting naphthenic acid corrosion test results show that Inconel 625 cladding layer has the lowest corrosion rate and the best corrosion resistance,compared to the most current commonly used material in the refining unit.The singlelayer multichannel laser cladding on the surface of carbon steel of Inconel 625 alloy powder was realized and finally obtained The process parameters of the laser multichannel lap cladding with relatively high cladding efficiency and smoothing and no defects surface.