The invention discloses an integrated stainless steel-
carbon steel composite tube and a preparation process and a
coating process of the integrated stainless steel-
carbon steel composite tube. The integrated stainless steel-
carbon steel composite tube and the preparation process and the
coating process of the integrated stainless steel-carbon steel composite tube mainly solve the problems that connection between base
layers and composite
layers of a lining tube, a bonding tube and a press fit tube is not firm, layering can occur easily, and performance is poor in the prior art. The integrated stainless steel-carbon steel composite tube comprises four
layers of structures which are a stainless steel layer, a stainless steel-carbon steel
mixed layer, a carbon steel layer and an
epoxy resin layer in sequence from inside to outside. The stainless steel-carbon steel
mixed layer is of an integrated structure formed by stainless steel and carbon steel in a metallurgical
smelting mode, the stainless steel layer and the stainless steel-carbon steel
mixed layer are of an integrated structure, and the carbon steel layer and the stainless steel-carbon steel mixed layer are of an integrated structure; the thickness ratio of the stainless steel layer to the carbon steel layer is 1:10. A beveled edge is further formed in the end of the integrated stainless steel-carbon steel composite tube, and the angle of the beveled edge ranges from 30 degrees to 35 degrees. The integrated stainless steel-carbon steel composite tube is simple in structure, low in price and good in performance, thereby being suitable for popularization and application.