Diffusion Bonding Of Nickel-plated Carbon Steel To 304 Stainless Steel And Mechanical Properties Of The Cladding Sheet

Stainless steel-carbon steel clad plates can reduce the use of stainless steel in combination of corrosive resistance and excellent mechanical properties suitable for structural application in corrosive environments.Stainless steel clad plates at present are primarily manufactured by explosive welding and roll-cladding,while both of them have their own defects.Researches about stainless steel clad plate concentrates mainly on analyzing microstructures and properties of the weld joints but almost nothing about mechanical properties of the whole clad plates.Diffusion bonding technique has proved to be an effective forming process for joining similar and dissimilar materials,especially when their physicochemical properties vary widely.In this paper,carbon steel and 304 stainless steel were used as base and clad material,respectively.In a form of carbon steel in the middle with two pieces of stainless steels on the two out surfaces,stainless steel clad plates were prepared by diffusion bonding between the two kinds of steels followed by rolling and heat treatments.The effects of heat treatments and carbon steel thickness ratio on mechanical properties of clad plates were researched.The diffusion bonding results showed that similar interfacial structures formed on the interface of diffusion-bonded specimens.Owing to the diffusion of carbon atoms from carbon steel to 304 stainless steel,Cr₂₃C₆ precipitated on the stainless steel side,while decarburized layer formation was observed on the carbon steel side.During the diffusion bonding process,temperature,time,thickness of nickel interlayer and carbon content of carbon steel would only affect the growth rate of decarburized layer and carbide participation region but not their microstructures.Therefore,thickness of the diffusion-affected zone can be controlled by adjusting the parameters mentioned above.The diffusion-bonded clad plate cracked during hot-rolling process but can be cold-rolled.Next,the effects of heat treatments on the microstructures and properties of carbon steel-304 stainless steel clad plate were discussed.The results revealed that normal heat treatment procedures can be applied to stainless steel clad plates after cold-rolling,while the decarburized layer would still exist on the carbon steel side.Stainless steel clad plate with austenite on the surface and tempered martensite in the core can be obtained through the best heat treatment procedure involving quenching and tempering.Finally,the effects of carbon steel thickness ratio on properties of clad plates were researched.It was found that,under the experimental condition in this experiment,the tensile strength of clad plate can be expressed as the sum of product of the strength and thickness ratio of each component.