Evolution of Nonmetallic Inclusions in GCr15 Bearing Steels During Continuous Casting Process

Zhang, Yanhui; Gong, Cheng; Wang, Jujin; Yang, Wen

doi:10.1002/srin.202100445

Cited by 10 publications

(3 citation statements)

References 31 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The holding temperature of 740 • C (close to Ac 1 = 750 • C) makes the carbide and grain size of the steel uniform after quenching and low-temperature tempering, effectively reducing the stress concentration during impact loading, retarding crack growth and increasing impact toughness by 37% [17]. Besides, high-purity bearing steel is developed [18,19]. The process of low alkaline slag refining combined with vacuum carbon deoxidation can achieve TiN inclusion control and improve the cleanliness of GCr15 bearing steel [20], and methods such as ultrasonic shot peening [21][22][23] and ultrasonic rolling [24] are used to form gradient nanostructured surface layers on bearing steel, which can effectively improve the surface hardness and wear resistance of the steel, and also refine the lath martensite to obtain better mechanical properties.…”

Section: Introductionmentioning

confidence: 99%

Effect of Rare Earth Y on Microstructure and Mechanical Properties of High-Carbon Chromium Bearing Steel

Xu,

Liu,

Yang

et al. 2024

Metals

View full text Add to dashboard Cite

The effect of rare earth Y on the microstructure and properties of high-carbon chromium bearing steel in different heat treatment processes has been studied. The microstructure and mechanical properties of the bearing steel under hot rolled, annealed and quenched and tempered conditions were compared and analysed, focusing on the effect of inclusions on fatigue performance. The addition of rare earth Y improves the microstructure, Vickers hardness, tensile strength, impact toughness and fatigue properties of bearing steel. The results show that rare earth Y can refine and spheroidise cementite, make the distribution of cementite more uniform, enhance the strengthening effect of the second phase and reduce the stress concentration caused by the shape of cementite. At the same time, the formation of network cementite is inhibited and the harm to grain boundary is reduced. It also has a refining effect on the grain, and the refined grain can achieve better mechanical properties. In addition, by modifying the oxides and sulphides in the steel, the properties of the steel are also improved, particularly in the quenched and tempered state.

show abstract

Section: Introductionmentioning

confidence: 99%

Effect of Rare Earth Y on Microstructure and Mechanical Properties of High-Carbon Chromium Bearing Steel

Xu,

Liu,

Yang

et al. 2024

Metals

View full text Add to dashboard Cite

show abstract

“…Metallurgists have conducted significant research on inclusion control in bearing steel [8][9][10][11][12][13][14][15][16][17]. At present, there are two main methods for inclusion control in bearing steel, strong aluminium deoxidation [8][9][10][11][12][13][14][15], and weak siliconmanganese deoxidation [11,16,17]. In strong aluminium deoxidation, the total oxygen content in steel is low and the number of inclusions is small.…”

Section: Introductionmentioning

confidence: 99%

Thermodynamic model and mechanism of non-alloyed hydrogen deoxidation of GCr15 bearing steel

Lei

Zhu

Guo

et al. 2022

Ironmaking & Steelmaking

View full text Add to dashboard Cite

A new method of non-alloyed hydrogen deoxidation is proposed, and the hydrogen deoxidation of GCr15 is studied using thermodynamic modelling. Deoxidation by blowing hydrogen is dominated by hydrogen molecular, and the degree of deoxidation depends on p H2O p H2 , which is independent of [H]. Carbon and hydrogen will compete for deoxidation during the blowing of hydrogen. The deoxidation mode depends on the relationship between the actual p H2O p H2 and the critical p H2O p H2 . The system pressure has a great influence on the carbon / hydrogen deoxidation equilibrium. Under vacuum conditions, carbon has a stronger deoxidation ability than hydrogen. Finally, a new process for hydrogen deoxidation was proposed. In the later stage of converter smelting, hydrogen was blown to reduce the excess oxygen → tapping, and hydrogen was blown to alternate deoxidation of carbon and hydrogen → sufficient carbon powder was added into the ladle → RH treatment, and hydrogen was stopped to blown, and carbon deoxidation occurred.

show abstract

“…[1] Currently, there are two main methods to control cleanliness: Al deoxidation and Si-Mn nonaluminum deoxidization. Using the former, [2][3][4][5][6][7][8][9] oxygen content in the molten steel can be rapidly reduced by controlling the deoxidation conditions and high-basicity slag, while total oxygen (TO) can be reduced to less than 5 ppm. However, this introduces spinel and calcium aluminate inclusions, which reduce the fatigue life of bearing steel, causing nozzle clogging.…”

mentioning

confidence: 99%

Thermodynamics and Nucleation Kinetics Model of Nonalloyed Carbon Deoxidation of Bearing Steel

Lei

Zhu

Guo

et al. 2023

steel research int.

View full text Add to dashboard Cite

Bearing steel is an important primary manufacturing material for mechanical equipment widely used in the military, aerospace, and transportation industries. Owing to the rapid development of the economy and society, better fatigue life and stable quality of bearing steel are required by engineers. The quality of bearing steel is improved by an important factor, cleanliness, that is, total oxygen content and inclusion control. [1] Currently, there are two main methods to control cleanliness: Al deoxidation and Si-Mn nonaluminum deoxidization. Using the former, [2][3][4][5][6][7][8][9] oxygen content in the molten steel can be rapidly reduced by controlling the deoxidation conditions and high-basicity slag, while total oxygen (TO) can be reduced to less than 5 ppm. However, this introduces spinel and calcium aluminate inclusions, which reduce the fatigue life of bearing steel, causing nozzle clogging. The Si-Mn nonaluminum deoxidization [5,[10][11][12] solves the problem of nozzle clogging and reduces calcium aluminate and spinel inclusions in bearing steel from the source. However, owing to the weak Si-Mn deoxidization ability, the TO in molten steel is higher than that of Al-deoxidized bearing steel. Excess oxygen precipitates at the grain boundary in the form of oxide inclusions, which greatly affects the ductility and corrosion resistance of steel.For decades, metallurgical scholars have conducted studies on inclusions in bearing steel. However, producing nonmetallic inclusions either by Al deoxidation or Si-Mn deoxidation is inevitable. To improve the structural integrity of steel, it is necessary to remove [13][14][15][16][17] or modify [9,[18][19][20][21][22] the inclusions. Using ferroalloy deoxidization to control cleanliness does not solve the contradiction of reducing the oxygen content and avoiding inclusions, which limits the improvement of high-quality bearing steel. Therefore, a new design of cleanliness control for bearing steel is required.To solve these issues, the author proposed two methods for producing high-quality bearing steel: 1) hydrogen deoxidation [23,24] and 2) vacuum carbon deoxidation. [23] Xiao Wei [25] found that the TO content of Si-deoxidized bearing steel after ladle furnace (LF) refining is about 20-30 ppm, and after Ruhrstal and Heraeus (RH) vacuum carbon deoxidization, it is reduced to 8-10 ppm, far higher than the theoretical carbon deoxidization under vacuum conditions. The deoxidation product of carbon deoxidation is CO, which can be spontaneously discharged from the molten steel to avoid residual inclusions. This solves the technical problem of fatigue failure caused by inclusions due to deoxidation. The nonalloyed carbon deoxidation process uses C-O reaction to generate CO gas. Many studies on the C-O reaction mechanism [26] and CO nucleation [27,28] were conducted. However, these researches involve smelting ultralowcarbon steel and blowing oxygen into molten steel to achieve rapid decarburization, and studies on the smelting of high-carbon ultralow-oxygen steel by carbon...

show abstract

Evolution of Nonmetallic Inclusions in GCr15 Bearing Steels During Continuous Casting Process

Cited by 10 publications

References 31 publications

Effect of Rare Earth Y on Microstructure and Mechanical Properties of High-Carbon Chromium Bearing Steel

Effect of Rare Earth Y on Microstructure and Mechanical Properties of High-Carbon Chromium Bearing Steel

Thermodynamic model and mechanism of non-alloyed hydrogen deoxidation of GCr15 bearing steel

Thermodynamics and Nucleation Kinetics Model of Nonalloyed Carbon Deoxidation of Bearing Steel

Contact Info

Product

Resources

About