Transactions of Materials and Heat Treatment

Title：Influence of controlled rolling and controlled cooling process on microstructure and mechanical properties for S45C steel rod coil used in automobile shock absorber piston rods

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ClassificationCode：TG335.6

year,vol(issue):pagenumber：2023,48(10):15-153

Abstract：

For the problems of low strength and Widmanstatten structure of large-sized S45C steel hot-rolled rod coil, the influence of controlled rolling and controlled cooling on the microstructure and mechanical properties of rod coil was studied. The heating temperature, finisher entry temperature, coiling and controlled cooling temperature and cooling rate in the rolling process were optimized and adjusted, and the microstructure and mechanical properties of S45C steel hot-rolled rod coil under the original process and the optimized process were compared and analyzed. The results show that the tensile strength and hardness of the hot-rolled rod coil increase significantly after optimizing the process, increasing by 21 MPa and 3 HRB, respectively, while the elongation and section shrinkage increase slightly. The Widmanstatten structure of the rod coil rolled by the optimized process is basically disappeared, and the grain size is refined, the grain size increases from 7.0 grade to 8.0 grade.The pearlite lamellae is thinner and the lamellae spacing is reduced from 0.33 μm to 0.26 μm. By reducing the heating temperature and rolling temperature and controlling the cooling method, the strength of S45C steel hot-rolled rod coil is improved, and the Widmanstatten structure is improved.

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董庆（1982-），男，硕士，高级工程师 E-mail：badibt01@sina.com

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