Effect of Slag Composition on Fatigue Life of High Speed Wheel Steel

Abstract:

In order to improve fatigue life of wheel steel, secondary-refining process was done with Al-deoxidation and slag of high basicity, high Al2O3 content and low oxidizing property. By morphology observation and composition analysis with FESEM, it is found that during LF-VD process, by slag-steel-inclusion interaction, Al2O3 inclusions could transform to MgO-Al2O3 spinel, and later on to CaO-MgO-Al2O3 inclusions, which are inclined to be eliminated by floatation, lowering T[O] content to 0.0007%, enhancing fatigue life of wheel steel. By In-Situ observation with CONFOCAL laser scanning microscope, it is found that MnS precipitates during solidification process, which would core oxide inclusion to form MnS-oxide complex inclusion, contributing to fatigue life improvement of wheel steel. By INSTRON fatigue testing machine, it is found that by successful inclusion control, tested samples achieve ultra-high cycle of 108 above, realizing experimental purpose of improving fatigue life of wheel steel, boosting domestic production process of CRH high speed wheel steel.

• Periodical: Advanced Materials Research (Volume 675)
• Pages: 264-269
• DOI: https://doi.org/10.4028/www.scientific.net/AMR.675.264
• Online since: March 2013
• Authors: Yu Tang
• Keywords: Fatigue, Inclusion, Slag, Wheel Steel

References

[1] SUITO Hideaki, et al. Thermodynamics on Control of Inclusions Composition in Ultra-clean Steels. ISIJ International, 1996, 36 (5): 528-536.

DOI: 10.2355/isijinternational.36.528

[2] NISHIMORI H, et al. Bull. Jpn. Inst. Met., 1993, 1: 441.

[3] HOJO Masatake, et al. Oxide Inclusion Control in Ladle and Tundish for Producing Clean Stainless Steel. ISIJ International, 1996, 36(Supplement): S128-S131.

DOI: 10.2355/isijinternational.36.suppl_s128

[4] KIM Jong wan, et al. Formation Mechanism of Ca-Si-Al-Mg-Ti-O Inclusions In Type 304 Stainless Steel. ISIJ International, 1996, 36(Supplement): S140-S143.

DOI: 10.2355/isijinternational.36.suppl_s140

[5] JIANG Min, et al. Formation of MgO-Al2O3 inclusions in high strength alloyed structural steel refined by CaO-SiO2-Al2O3-MgO slag. ISIJ International, 2008, 48 (7): 885-890.

DOI: 10.2355/isijinternational.48.885

[6] OKUYAMA Goro, et al. Effect of Slag Composition on the Kinetics of Formation of Al2O3–MgO Inclusions in Aluminum.

[7] HOLAPPA L E K, et al. Inclusion Control in High-Performance Steels. Journal of Materials Processing Technology, 1995, 53: 177-186.

DOI: 10.1016/0924-0136(95)01974-j

[8] HIGUCHI Yoshihiko, et al. Inclusion Modification by Calcium Treatment. ISIJ International, 1996, 36 (Supplement): S151-S154.

DOI: 10.2355/isijinternational.36.suppl_s151

[9] KUSANO Yoshiaki, et al. Calcium Treatment Technologies for Special Steel Bars and Wire Rods. ISIJ International, 1996, 36 (Supplement): S77-S80.

DOI: 10.2355/isijinternational.36.suppl_s77

[10] YE Guozhu, et al. Thermodynamics and Kinetics of the Modification of Al2O3 Inclusions. ISIJ International, 1996, 36 (Supplement): S105-S108.

DOI: 10.2355/isijinternational.36.suppl_s105

[11] Murakami Y, Nomoto T, Ueda T. Factors influencing the mechanism of superlong fatigue failure in steels [J]. Fatigue & Fracture of Engineering Materials & Structures, 1999, 22(7): 581-590.

DOI: 10.1046/j.1460-2695.1999.00187.x

[12] Murakami Y, Nomoto T, Ueda T, et al. On the mechanism of fatigue failure in the superlong life regime [J]. Fatigue & Fracture of Engineering Materials & Structures, 2000, 23(11): 893-910.

DOI: 10.1046/j.1460-2695.2000.00343.x

[13] Murakami Y, Yokoyama N, Nagata J. Mechanism of fatigue failure in ultra-long life regime [J]. Fatigue & Fracture of Engineering Materials & Structures, 2002, 25(8): 735-746.

DOI: 10.1046/j.1460-2695.2002.00576.x

[14] Murakami Y, Matsunaga H. Effect of hydrogen on high cycle fatigue properties of stainless steels and other steels used for fuel cell system [C]. Proceedings of the Third International Conference on Very High Cycle Fatigue, Kyoto, 2004: 322-333.

DOI: 10.1016/j.ijfatigue.2005.06.059