The inclusion type, and the relationship between inclusions and the total oxygen, and the ways of decreasing the inclusion count and controlling the inclusion evolution are studied. The results are shown as follows: when the slag composition is controlled in an appropriate range, the slag melting point is low and the ability of deoxidation and inclusion absorption are good. The total oxygen is proportional to the count of 0–6 μm inclusions in the unit area. The mixing of the ladle and the removal of inclusion were promoted by optimising the ladle field. By Mg or Ca treatment, the size of Al2O3 inclusions can be reduced. But the large size CaO inclusions may be brought into steel by the Ca treatment.
This paper is part of a Themed Issue on Recent developments in bearing steels.
LundT. and ÅkessonJ.: ‘Oxygen content, oxidic microinclusions, and fatigue properties of rolling bearing steels’, in ‘Effect of steel manufacturing processes on the quality of bearing steels’, (ed. HooJ. J. C.), 308–330; 1986, Phoenix, AZ, ASTM Spec. Tech. Puble., No. 987, American Society for Testing and Materials.
2.
HashimotoK., FujimatsuT., TsunekageN., HiraokaK., KidaK. and Costa SantosE.: ‘Study of rolling contact fatigue of bearing steels in relation to various oxide inclusions’, Mater.Des., 2011, 32, 1605–1611.
3.
HashimotoK., HiraokaK., KidaK. and Costa SantosE.: ‘Effect of sulphide inclusions on rolling contact fatigue life of bearing steels’, Mater. Sci. Technol., 2012, 28, 39–43.
4.
KawakamiK.: ‘Clean bearing steel, technology for control of nonmetallic inclusions and production of clean steels’, NMS-ISIJ, 2004, 182/183, 153–179.
5.
UesugiT.: ‘Recent development of bearing steel in Japan’, Tetsu-to-Hagane, 1988, 74, 1889–1894.
6.
AkashiG., DoiK., MatsushimaY., TakagiI. and FukuzakiY.: ‘Production of high-carbon ball and roller bearing steel in BOF-LF-CC process’, Wire J. Int., 1999, 32, 92–97.
7.
FarajiM., WilcoxD. P., ThackrayR. P., ToddI., HoweA. A. and TsakiropoulosP.: ‘Effect of early stages of thermomechanical processing on inclusions in high carbon steel’, Mater. Sci. Technol., 2014, 30, 1177–1188.
8.
HamedanyA. A.: ‘Fatigue model of bearing steel based on stressed volume’, Mater. Sci. Technol., 2015. 1743284715Y-0000000113.
9.
WalkerP. F. F.: ‘Improving the reliability of highly loaded rolling bearings: the effect of upstream processing on inclusions’, Mater. Sci. Technol., 2014, 30, 385–410.
10.
NumataM., HiguchiY. and FukagawaS.: ‘The change of composition of inclusion during Ca treatment’, Tetsu-to-Hagané, 1998, 84, 159–164.
11.
TakenouchiT. and SuzukiK.: ‘Influence of Ca–Al deoxidizer on the morphology of inclusions’, Tetsu-to-Hagané, 1976, 62, 1653–1667.
12.
DanT. and GunjiK.: ‘Deoxidation characteristics and shape modification of deoxidation products with Al–Ce and Al–Y complex deoxidizers’, Tetsu-to-Hagané, 1982, 68, 1915–1921.
13.
KimJ. S., KawakamiM. and TanidaK.: ‘Effect of Ar bubbling on removal rate of alumina inclusion in Al deoxidized steel’, Tetsu-to-Hagané, 1995, 81, 167–172.
14.
NaraiH., AbeT., FurumuraK., NishimoriH., KobayashiK. and TsubotaK.: ‘Fatigue properties of extremely purified bearing steels’, CAMP-ISIJ, 1992, 5, 1959–1960.
15.
LiuH. Y., WangH. L., LiL., ZhengJ. Q., LiY. H. and ZengX. Y.: ‘Investigation of Ti inclusions in wire cord steel’, Ironmaking Steelmaking, 2011, 38, 53–58.
16.
MinW., YanpingB. and HengC.: ‘The composition and morphology evolution of oxide inclusions in Ti-bearing ultra low-carbon steel melt refined in the RH process’, ISIJ Int., 2010, 50, 1606–1611.
17.
JonssonP. G., JonssonL. and SichenD.: ‘Viscosities of LF slags and their impact on ladle refining’, ISIJ Int., 1997, 37, (5), 484–491.
18.
YoonB.-H., HeoK.-H., KimJ.-S. and SohnH.-S.: ‘Improvement of steel cleanliness by controlling slag composition’, Ironmaking Steelmaking, 2002, 27, 215–219.
19.
NakanishiK., FujiiT. and SzekelyJ.: ‘Quality and yield improvement using method of blowing argon stirring’, Ironmaking Steelmaking, 1995, 22, 193–196.
