Effects of Yttrium on the Microstructure and Properties of 20MnSi Steel

The effects of rare earth (RE) on the microstructure and mechanical properties of a pearlitic steel wire rod have been investigated under the dual low‐oxygen condition. The results show that the wire rods with different RE contents all have pearlite microstructure. As RE content increases from 0 to 310 ppm, the pearlite substructures such as interlamellar spacing, pearlite colony size and ferrite grain size decreasing remarkably, indicating that the nucleation and growth behavior of pearlite have changed. This is attributed to the combined effects of stimulating nucleation by large number of micrometer scale RE‐containing inclusions and decreased carbon diffusion due to RE in solution. As a results, the changes in microstructure lead to simultaneous enhancement of strength, plasticity, impact toughness and microhardness of pearlite wire rod, demonstrating that adding appropriate content of RE under the dual low‐oxygen condition is an effective alloying method to optimize the microstructure and mechanical properties of pearlitic steel wire rod.This article is protected by copyright. All rights reserved.

Section: Discussionmentioning

confidence: 99%

Effects of Rare Earth on the Microstructure and Mechanical Properties of a Pearlitic Steel Wire Rod

Yang

Zhang

Sang

et al. 2023

“…For example, the addition of elements such as Cr, Mo, and Ni can improve the steel microstructure and increase the stability of passivation films, thus enhancing the corrosion resistance of the steel. [6][7][8] It has been proven that rare earth (RE) elements can significantly improve the cleanliness [9] and microstructure [10] of steel. For example, Liu et al [11] reported that by adding 0.022 wt% of RE to 718 steel, the O content was reduced from 15 ppm to 6 ppm, and the inclusions were changed from MnS and Al 2 O 3 to RE 2 O 3 , RES, RE 2 O 2 S, and REAlO 3 .…”

Section: Introductionmentioning

confidence: 99%

“…It has been proven that rare earth (RE) elements can significantly improve the cleanliness [ 9 ] and microstructure [ 10 ] of steel. For example, Liu et al [ 11 ] reported that by adding 0.022 wt% of RE to 718 steel, the O content was reduced from 15 ppm to 6 ppm, and the inclusions were changed from MnS and Al 2 O 3 to RE 2 O 3 , RES, RE 2 O 2 S, and REAlO 3 .…”

Section: Introductionmentioning

confidence: 99%

Effect of Ce on Inclusions and Precipitates in 10Cr5MoV Steel and the Microscopic Behavior of Solid Solution Ce in Steel

Shi,

Ren,

et al. 2024

In this article, the effects of Ce (0–120 ppm) on inclusions and precipitates in industrially produced CO2/H2S‐resistant 10Cr5MoVCe special oil well pipe steel and the microscopic behavior of Ce solid solution in steel were systematically studied by scanning electron microscopy, transmission electron microscopy, electrolysis separation of nonaqueous mixed solutions, and first‐principles calculations. After adding Ce to 10Cr5MoV steel the inclusions changed from chain‐like Al2O3 inclusions to polygonal Ce–O–S–Al–Ca complex inclusions and spheroidal Ce2O3, CeAlO3, Ce2O2S, and CeS inclusions. When the total Ce content was 25–120 ppm, the solid solution Ce content was maintained at about 20% of the total Ce content. The Ce had no significant influences on the types of chromium carbide precipitates, and the chromium carbide precipitates of all tested steels were Cr23C7 and Cr7C3. However, with the increase of Ce, the content of Cr23C7 and Cr7C3 precipitates decreased slightly, from 1.27% without Ce to 1.18% when Ce was 120 ppm. The first‐principles calculation results show that there was strong interaction between Fe, Ce, and Cr. Ce enhanced the interaction force between the Fe and Cr atoms, and improved the stability of the system, which facilitated the solid solution of Cr in the Fe–Cr system.

“…[ 12–17 ] Besides, the microstructure and property of steels could be significantly improved by an appropriate addition of rare earth elements. [ 18–23 ] Li et al [ 24 ] found that the evolution path of a Si‐Al killed 253 MA steel was Si–Al–O→Ce 2 O 3 (Ce 2 O 2 S) →Ce–Si–Al–O, which was in liquid state under 1773 K. Ren et al [ 25 ] found that when the cerium content in an aluminum‐killed steel increased from 0 to 280 ppm, the modification sequence of inclusions was Al 2 O 3 → CeAlO 3 → Ce 2 O 2 S → Ce 2 O 2 S and CeS. Li et al [ 26 ] found that the undercooling degree of a 1045 steel could be reduced by cerium‐containing inclusions, and the equiaxed grain zone in the cast steel was enlarged after additions of rare earth elements.…”

Section: Introductionmentioning

confidence: 99%

“…[12][13][14][15][16][17] Besides, the microstructure and property of steels could be significantly improved by an appropriate addition of rare earth elements. [18][19][20][21][22][23] Li et al [24] found that the evolution path of a Si-Al killed 253 MA steel was Si-Al-O!Ce 2 O 3 (Ce 2 O 2 S) !Ce-Si-Al-O, which was in liquid state under 1773 K. Ren et al [25] found that when the cerium content in an aluminum-killed steel increased from 0 to 280 ppm, the modification sequence of inclusions was Al 2 O 3 ! CeAlO 3 !…”

mentioning

confidence: 99%

Effects of Cerium Addition on Inclusions and Solidification Structure of a Low‐Nickel Si–Mn‐Killed Stainless Steel

Zhang

Ren

Huang

et al. 2023

The effect of cerium on inclusions and solidification structure of a low‐nickel Si–Mn‐killed stainless steel is studied using laboratory experiments. When the cerium content in steel increased from 0 to 250 ppm, modification sequence of inclusions is Si–Mn(–Al)–O and MnS → Ce–Si–Mn–O–S → Ce(–Si)–O–S → CeS and CeC2. The number density and area fraction of inclusion first decrease with the increase in the cerium content and then increase due to the formation of CeC2 inclusions when the cerium content is bigger than 150 ppm, which is precipitated in solid steel during solidification. When the cerium content increases from 0 to 250 ppm, the fraction of equiaxed grain zones of steel ingot first increases and reaches a maximum value when the cerium content is 54 ppm; then the fraction of equiaxed grain zones decreases with the increase of the cerium content. 2D lattice misfit calculations are performed and it is found that there are no heterogeneous nucleation cores in the steel without cerium during solidification. For the steel with cerium, Ce4.67Si3O13, Ce2O2S, and CeS inclusions act as heterogeneous nucleation cores, increasing the fraction of the equiaxed grain zone. Bigger effective heterogeneous nucleation cores number density leads to a larger fraction of the equiaxed grain zone.