Experimental and computational investigation of weathering steel Q450NQR1 under high cycle fatigue loading via crystal plasticity finite element method

Microstructure evolution and mechanical properties of two kinds of weathering steel welded joints

“…The raw materials in this investigation are two weathering steels, Q450NQR1 and Q450AWR5, which are produced by China's Ansteel group for high‐speed train structures. The main characteristics of Q450NQR1 are low‐alloy structural steel with protective rustproof layer and resistance to atmospheric corrosion, which can be used for manufacturing steel structures such as vehicles and bridges 4 . The chemical composition of Q450NQR1 is 0.062 C, 0.261 Si, 1.01 Mn, 0.013 P, 0.001 S, 0.03 Al, 0.186 Ni, 0.17 Cr, 0.296 Cu, and balance Fe (wt.…”

“…3 Weathering steel is made by adding a certain amount of Cu, P, Cr, Ni, and other alloying elements to the steel, which has the excellent atmospheric corrosion resistance of low-alloy steel. 4 Weathering steel is becoming increasingly favored around the world because it reduces the overall cost of steel structures over their life cycle. 5 Q450NQR1 and Q450AWR5 are two weathering steels that are widely used in welding train structures to reduce the weight of trains.…”

“…Under the environment‐friendly background of “emission peak” and “carbon neutrality,” 2 the demand for high‐strength weathering steel is becoming more and more important to meet the comprehensive transportation performance of trains owing to the increasing requirements for lightweight and low‐cost maintenance 3 . Weathering steel is made by adding a certain amount of Cu, P, Cr, Ni, and other alloying elements to the steel, which has the excellent atmospheric corrosion resistance of low‐alloy steel 4 . Weathering steel is becoming increasingly favored around the world because it reduces the overall cost of steel structures over their life cycle 5 …”

Analysis and Modeling of Stress–Strain Curves in Microalloyed Steels Based on a Dislocation Density Evolution Model

“…An analytic model for the dislocation density evolution accounting for dislocation generation, storage, and dynamic recovery mechanisms in polycrystals with solely isotropic material behavior was developed by Hunter and Preston [ 28 ]. Zhao et al [ 29 , 30 ] suggested a model for the overall dislocation density evolution and stress relaxation due to dynamic recovery and recrystallization after hot deformation, but the approach excludes three-dimensional plastic deformation. Buzolin et al [ 31 ] proposed a model to account for the dislocation density evolution during the hot deformation of titanium alloys.…”

“…This comprehensive approach requires full characterization of the microstructure, and therefore can hardly be applied to materials with allotropic transformation. For crystal plasticity, finite element simulation of stress–strain curves, as well as constitutive models—which often require numerous fitting parameters—are discussed in the literature [ 30 , 32 , 33 , 34 ].…”