Numerical Simulation And Experimental Study On The Composite Technology Of Submerged Arc Surfacing And Laser Cladding

At present,most of the remanufacturing of rolls in the metallurgical industry adopts a relatively single surface strengthening modification technology,which mainly includes surfacing welding,thermalspraying,thermalspray welding,etc.Among them,submerged arc surfacing is the most widely used technology in roll remanufacturing.Although traditional submerged arc surfacing technology can achieve large-scale repairs and has good adaptability to alternating stress conditions,the welded structure obtained is relatively high.Coarse,severe alloy segregation and high dilute on rate make this technology have certain application limitations.Laser cladding technology is an emerging green surface strengthening technology.Compared with the surfacing process,laser cladding has the advantages of fast heating and fast cooling,which can obtain finer grain coating with high bonding strength,compact structure and low dilution ratio.Combining submerged arc surfacing and laser cladding technology can realize the remanufacturing of roller,which can give full play to the complementary advantages of the two processes and produce excellent repair effect.This paper aims to explore the feasibility of roll remanufacturing technology undersubmerged arc surfacing and laser cladding combined process.Through comprehensive application of numerical simulation and experimental methods,the submerged arc surfacing and laser cladding combined process are studied in-depth,and the transient mechanism of physical and metallurgical behavior during manufacturing process is revealed.Finally,the material microscopic characterization experiment of submerged arc surfacing and laser cladding combined process is carried out.It provides theoretical guidance for the practical application of the two processes combination and has important practical significance and application value.The main research contents are as follows:(1)Based on the multi-physical field coupling finite element platform,the thermal-elastic-plastic coupling model of submerged arc surfacing process for roll is established,and the calculation reveals the evolution law of temperature and stress of the base and surfacing layer during surfacing process.By establishing a heat-fluid coupling model,the evolution process of the surfacing molten pool from initiation,growth to steady state is calculated,and the influence of electromagnetic force and surface tension on the flow field distribution and shape of the molten pool is analyzed.(2)Establish a multi-field coupling model for roll repair under the coupling process of submerged arc surfacing and laser cladding,and explore the feasibility of roll remanufacturing by the composite process.Based on the Arbitrary Lagrangian-Eulerian dynamic mesh method and the elastic-plastic material model,the laser cladding process temperature,the flow rate of the molten pool and the transient evolution law of the surfacing layer stress are calculated based on the surfacing process.(3)Used the Monte Carlo method,the sensitivity of the submerged arc surfacing and laser cladding process parameters to their temperature,temperature gradient changes and stress effects was calculated and analyzed,and the submerged arc surfacing and laser cladding process parameters were optimized.(4)The related experimental research of submerged arc surfacing welding and laser cladding composite technology was carried out.Firstly,surfacing welding was carried out on the surface of roller base,and the surfacing welding surface was annealed and mechanically leveled and laser cladding was carried out on the surfacing welding surface.Throughs EM scanning electron microscope,XRD diffractometer and microhardness tester,the material characterization experiment of the composite process strengthening layer was carried out,and the micromorphology,phase composition and hardness distribution were analyzed.