Study On Forming Mechanism And Properties Of 316L Arc Additive Remanufacturing

Austenitic stainless steel of 316 L is a material that is widely employed,following 304 stainless steel.Its non-magnetic qualities,corrosion resistance,and high heat tolerance make it an ideal choice,so it is widely utilized in the marine,petrochemical and other related industries.At present,a large number of 316 L stainless steel parts scrapped due to local damage,due to the limitation of repair technology,damaged parts can only be remelted,cast,reprocessing,not only improve the production cost,but also reduce the processing efficiency.Additive remanufacturing,as an alternative,can provide an efficient,low-cost repair method for parts that fail due to local damage.As a type of additive manufacturing technology,arc additive manufacturing is developed based on welding technology.This technology not only boasts high forming efficiency and low manufacturing cost with short production cycles,but also enables in situ manufacturing without being constrained by part size,making it ideal for repairing large parts.However,the existing researches mainly focus on the arc additive forming of integral parts,and there are few researches on the reforming of 316 L stainless steel on the 316 L stainless steel matrix manufactured by traditional methods.Therefore,the feasibility evidence of using arc additive manufacturing technology to repair parts is still insufficient.In this paper,arc additive remanufacturing of 316 L stainless steel on 316 L substrate manufactured by traditional methods is studied.First,the range of current intensity and welding speed for surface response,numerical simulation and forming experiments was determined by arc additive single-layer single-channel experiments.Based on Minitab data analysis and statistics software,surface response experiments of input parameters and forming characteristics of arc additive manufacturing were carried out.The response factors chosen were the current intensity and welding speed,while the test indices selected included penetration depth,width,and residual height of the weld to investigate the influence of welding current intensity and speed on these parameters.A bidirectional prediction model was developed to establish a relationship between welding current intensity and speed with penetration depth,width,and residual height.Then,a finite element model for arc additive manufacturing process was established using Comsol’s solid heat transfer and mechanics module,along with moving heat source technology and life-death element method.The thermal and mechanical physical field coupling modeling method was employed to obtain the distribution law of temperature field and stress field of 316 L arc additive manufacturing process under different current intensities.Finally,through the experimental method,the universal tensile testing machine,metallographic microscope,scanning electron microscope and other equipment are used to process and test the samples formed under different current strengths and the samples cooled by different ways after solution treatment.The effects of different forming parameters and cooling methods after solution treatment on mechanical properties and microstructure of arc additive remanufacturing samples were studied.