Effects of Zirconium on the Structure and Mechanical Properties of High‐Strength Low‐Alloy Steels under Quenched or Tempered Conditions

Abstract

The effects of zirconium (Zr) on the microstructure, inclusions, Vickers hardness, impact toughness, and tensile properties of quenched and tempered high‐strength low‐alloy (HSLA) steels are investigated. The results show that the addition of Zr is beneficial to the refinement of the grain size of HSLA steels under the two heat treatment conditions. When the Zr content is 0.2 wt%, the average grain size of the steel is the smallest. The main inclusions in Zr‐containing HSLA steels are Zr–O and Zr–O–Mn–S, and the distribution of inclusions in HSLA steels is the most uniform when the Zr content is 0.04 wt%. The addition of an appropriate amount of Zr improves the Vickers hardness of HSLA steels under two heat treatment conditions. In terms of impact toughness, the increase of Zr content is beneficial to improving the room‐temperature impact energy of HSLA steels under two heat treatment conditions, but the improvement of the impact properties of tempered HSLA steels is limited. For tensile properties, the addition of 0.04 wt% Zr is beneficial to increasing the strength of quenched or tempered HSLA steels.

Study on Microstructure and Mechanical Properties of Marine 10Ni5CrMoV Steel during Tempering

“…The dislocation strengthening σ dis of the specimens at different tempering temperatures can be calculated using Bailey-Hirsch relation: [39] Δσ dis ¼ Mαμbρ 1=2 (7) where M is the average Taylor factor (M = 3), α is a constant (α = 0.24), b is the shear modulus of martensite matrix (76 GPa), [40] b is the Burgers vector of the dislocation (0.25 nm), ρ is the dislocation density, which can be measured by XRD, as shown in Figure 5d. Dislocation strengthening decreases as the dislocation density decreases.…”

Effect of Coiling Temperature on Microstructures and Precipitates in High-Strength Low-Alloy Pipeline Steel after Heavy Reduction during a Six-Pass Rolling Thermo-Mechanical Controlled Process

“…High-strength low-alloy (HSLA) steel is regarded as a series of low-carbon steel microalloyed with V, Nb, or Ti, with a yield strength reaching 690 Mpa [1][2][3][4]. HSLA steels are extensively utilized for several engineering applications due to their high yield strength and cold formability [5][6][7].…”

“…In particular, CT is known to have Metals 2024, 14, 249 2 of 17 a strong effect on nano-scale precipitates [19][20][21][22][23]. For Nb-Ti HSLA pipeline steel, Nb and Ti play a significant role in achieving their strength [3,24], as the precipitation of Nb and Ti is very sensitive to CT [19,20]. For Nb-Ti micro-alloyed steel, the precipitates begin to form at a CT of 675 • C. The intermediate precipitates are small in size and randomly distributed in the matrix at a CT of 650 • C [20][21][22][23][24][25].…”

Effect of Magnesium Treatment and Cooling Method on Manganese Sulfide in U75V Heavy‐Rail Steel Deoxidized by Si–Mn

“…Furthermore, this inclusion exhibits less deformation during hot processing, and the steel has good cutting performance; thus, the transverse mechanical properties of the steel are less affected. Therefore, controlling the size, shape, quantity, and distribution of MnS inclusions in steels is important.Currently, the control of MnS is primarily divided into four types: 1) adding strong deoxidizing elements such as Ti, [6][7][8][9] Mg, [10,12] and Zr [13][14][15] to molten steel. Several fine oxides are formed in the molten steel, which can function as the nucleation core of MnS.…”

“…Currently, the control of MnS is primarily divided into four types: 1) adding strong deoxidizing elements such as Ti, [6][7][8][9] Mg, [10,12] and Zr [13][14][15] to molten steel. Several fine oxides are formed in the molten steel, which can function as the nucleation core of MnS.…”