Small‐Batch Industrial Hot‐Rolling Experiment Research on 304 Stainless Steel Welded Tube–HRB400E Carbon Steel Composite Screw‐Thread Steel Bars Properties

The investigation selects standardized 304 stainless steel welded tubes (SS‐WTs) with lower cost and HRB400E carbon steel (CS) round bars in the market, adopting the clean interface nonoxidation technology to prepare composite round blanks, then a small‐batch industrial hot‐rolling experiment is carried out to prepare Φ16 mm composite screw‐thread steel bars and obtain the samples of rough rolling (F1), medium rolling (F2) and finished products (Fp). The interfaces of F1, F2, and Fp are well combined, and the average cladding thicknesses are 3.54, 1.61, and 0.76 mm, and the circumferential nonuniformity coefficient ( C n) of cladding improves during medium rolling process (1.51–1.42), while it intensifies during finishing rolling process (1.42–2.94). The interfacial shear strengths of F1 and F2 are 565 and 485 MPa, respectively, which is significantly influenced by the elemental diffusion distances. The bending process of Fp presents a multipeak phenomenon and the maximum loading force is 24.78 KN. The yield strength, tensile strength, and break elongation of Fp are 532, 703 MPa, and 28.7%, respectively. The article has successfully achieved in conducting small‐batch industrial hot rolling of CSS bars by employing low‐cost 304 SS‐WTs and can also provide a theoretical basis and technical support for promoting large‐scale industrial rolling.