Application of Al-Mg Alloy in Bearing Steel

2009 ◽  
Vol 620-622 ◽  
pp. 387-390 ◽  
Author(s):  
Wei Gong ◽  
Zhou Hua Jiang ◽  
Dong Ping Zhan
Keyword(s):  
Oxygen Content ◽  
Spherical Shape ◽  
Inclusion Size ◽  
Bearing Steel ◽  
Mg Alloy ◽  
Total Oxygen ◽  
Total Oxygen Content ◽  
Alumina Inclusion ◽  
Inclusion Modification ◽  
Inclusions In Steel

There is less study about the effect of magnesium on characteristics of bearing. In the paper, the bearing steel was modified by three types of Al-Mg alloys. Firstly, the total oxygen content value was measured, and then the inclusion size, shape and chemical composition were analyzed by optical microscopy, SEM and EDX. The results show that, after treated by Al-Mg alloy, the total oxygen content descends remarkably and the alumina inclusion with big size and different shapes transform into spinel with small size and spherical shape. The optimal effect of inclusion modification is acquired after treated by NO. 3 Al-Mg alloy containing 16.55 wt% Mg, most of the inclusions in steel are spinel and magnesia, and the size of 96.23 wt% inclusions is less than 3μm.

Formation and Control of Inclusions during Steelmaking Process

2011 ◽  
Vol 52-54 ◽  
pp. 1681-1686 ◽  
Author(s):  
Yang Li ◽  
Zhou Hua Jiang ◽  
Shi You Yin ◽  
Ying Zhuang ◽  
Ming Li
Keyword(s):  
Oxygen Content ◽  
Bearing Steel ◽  
Spring Steel ◽  
Refining Process ◽  
Steelmaking Process ◽  
Total Oxygen ◽  
Total Oxygen Content ◽  
Oxide Inclusions ◽  
Deoxidation Process ◽  
Lf Refining

The variation of non-metallic inclusions and total oxygen contents in different steel grades were investigated by taking samples in steelmaking process, including gear steel, anchor chain steel, hard wire steel, bearing steel and spring steel. The inclusions mainly were Al2O3, MnS, and their composite inclusions in aluminum killed steel at the beginning of LF refining due to addition of FeAl alloy during the tapping from EAF and feeding of Al wire in LF process, and then Al2O3 inclusion changed to the Al2O3 - CaO composite inclusions after feeding of SiCa wire. The inclusions at the beginning of LF refining mainly were MnS, SiC and their composite inclusions in non-aluminum killed steel due to addition of the composite deoxidation and slagging agents (mainly including CaC2 and SiC) when EAF taping, while the inclusions in tundish mainly were MnS, CaO - SiO2 - Al2O3 composite oxide - sulfide inclusions. It is showed that the inclusions in bearing steel and spring steel samples were mainly globular oxide inclusions and silicate inclusions with higher rated results. Therefore, the refining process should be improved to remove globular oxide inclusions. The inclusions in molten steel were controlled by enhancing the diffusion deoxidation process, adjusting and controlling the basicity and composition of refining slags, respectively, and satisfactory results were obtained. The industrial test shows that the total oxygen content of the aluminum killed steel in the test heat after feeding wire reached the minimum value, which indicates that the optimized slag has a strong ability of absorbing Al2O3 inclusions. For non-aluminum killed steel, the total oxygen content was 0.0027 % to 0.0029 % in rolled products. The inclusions in the end of refining and rolled product were small and dispersed composite inclusions, and the separate Al2O3 inclusions can not be found in the non-aluminum killed steel after optimization of the refining process.

Secondary Steel Refining for Continuous Sequence Bloom Casting for High Oxide Cleanness Final Products

2012 ◽  
Vol 57 (1) ◽  
pp. 347-353 ◽  
Author(s):  
B. Zdonek ◽  
I. Szypuła ◽  
J. Kozłowski ◽  
S. Szczęch
Keyword(s):  
Continuous Casting ◽  
Oxygen Content ◽  
Equivalent Diameter ◽  
Process Technology ◽  
Total Oxygen ◽  
Total Oxygen Content ◽  
Continuous Sequence ◽  
Metallic Inclusions ◽  
Steel Refining ◽  
Inclusions In Steel

Secondary Steel Refining for Continuous Sequence Bloom Casting for High Oxide Cleanness Final ProductsSteelmaking and secondary refining process technology of resulphurized liquid steel with low content of total oxygen, assigned for continuous casting of strands for rolled and forged products for automotive industry was developed. The influence of secondary steel refining parameters on total oxygen content as well as amount and morphology of non-metallic inclusions was examined. It was found, that content of total oxygen and amount of non-metallic inclusions in steel decrease as steel refining time in the ladle becomes longer, and the chemical composition of non-metallic inclusions in steel changes from modified calcium aluminates to spinel inclusion of CaO·Al2O3·MgO type. The total oxygen content in steel from continuous casting in four cast sequence ranged from 6 to 25 ppm, with percentage share of non-metallic inclusions from 0.09 to 0.30 per cent and equivalent diameter 0.78 to 1.59 μm.

scholarly journals Study on Inclusions Distribution and Cyclic Fatigue Performance of Gear Steel 18CrNiMo7-6 Forging

Metals ◽  
2020 ◽  
Vol 10 (2) ◽  
pp. 201 ◽  
Author(s):  
Min Wang ◽  
Wei Xiao ◽  
Peng Gan ◽  
Chao Gu ◽  
Yan-Ping Bao
Keyword(s):  
Oxygen Content ◽  
Fatigue Failure ◽  
Three Dimensional ◽  
Inclusion Size ◽  
Cyclic Fatigue ◽  
Critical Value ◽  
Fatigue Performance ◽  
Total Oxygen ◽  
Total Oxygen Content ◽  
Gear Steel

The three-dimensional morphologies of inclusions in gear steel 18CrNiMo7-6 forging were investigated by a non-destructive extraction method, and the cleanliness of radial positions was analyzed, mainly including the variation of total oxygen content and the distribution of size and quantity of inclusions. In addition, fatigue performance was tested using an ultrasonic fatigue machine to investigate the fatigue characteristics of the steel. The results show that the quantity density of inclusions per unit volume in gear steel 18CrNiMo7-6 decreases exponentially with increasing size, oxide inclusions with a size less than 8 μm account for more than 90%, while sulfide inclusions account for more than 85%. The average value of the oxygen content can reflect the level of inclusions that were evenly distributed in the molten steel, and the accumulative total oxygen content increases significantly with increasing inclusion size. The fatigue specimen failed after the stress exceeded the critical value, and fatigue failure hardly occurred when the stress was below the critical value. Meanwhile, large-sized nondeformable inclusions such as Al2O3-CaO in gear steel 18CrNiMo7-6 are closely related to fatigue failure. It is recommended that the area from the center to the 1/2 radius with low cleanliness should be avoided, while the area from the 3/4 radius to the edge with high cleanliness should be selected during the machining of the gear.

scholarly journals Effect of Acid Slag Treatment on the Inclusions in GCr15 Bearing Steel

2019 ◽  
Vol 38 (2019) ◽  
pp. 760-766
Author(s):  
Yang Liu ◽  
Jing Li ◽  
Jinpeng Ge ◽  
Dingli Zheng
Keyword(s):  
Spatial Distribution ◽  
Melting Point ◽  
Oxygen Content ◽  
Bearing Steel ◽  
Refining Slag ◽  
Slag Treatment ◽  
Gcr15 Bearing Steel ◽  
Inclusions In Steel

AbstractBy laboratory slag/steel reaction equilibrim experiments, the viriation of oxygen content, inclusion compositions and inclusion sizes were studied. The effect of acid slag treatment on the transition mechanisms of D-type inclusions and the precipitation of TiN inclusions in GCr15 bearing steel were explored. The obtained results showed that the dominant inclusions in steel were plastic and smaller Al2O3-SiO2-MnO. The melting point were lower than 1400°C treated by the acid refining slag of 35.1%CaO-15%Al2O3-43.9%SiO2-6%MgO and there was no TiN found. The evolution of MgO·Al2O3 inclusions is: MgO·Al2O3→ MgO·Al2O3·SiO2·MnO→ Al2O3·SiO2·MnO. Mg and Al from MgO·Al2O3 inclusions were displaced by [Si] and [Mn] in steel liquid , and formation of plastic Al2O3-SiO2-MnO inclusions finally, whose compositions distribution were uniform. Mg and Si, Mn were complementary in inclusions as to the spatial distribution.

Refining Total Oxygen Content in the Solid Soil Phase

2019 ◽  
Vol 74 (3) ◽  
pp. 99-104
Author(s):  
Yu. N. Vodyanitskii ◽  
A. T. Savichev
Keyword(s):  
Oxygen Content ◽  
Total Oxygen ◽  
Total Oxygen Content ◽  
Solid Soil

Cavity Formation in Iron Oxide

CORROSION ◽  
1958 ◽  
Vol 14 (1) ◽  
pp. 57-64 ◽  
Author(s):  
D. W. JUENKER ◽  
R. A. MEUSSNER ◽  
C. E. BIRCHENALL
Keyword(s):  
Iron Oxide ◽  
Oxygen Content ◽  
High Temperatures ◽  
Diffusion Path ◽  
Deep Oxidation ◽  
Oxygen Atmosphere ◽  
Cavity Formation ◽  
Total Oxygen ◽  
Total Oxygen Content ◽  
Scale Thickness

Abstract A study is made of the deep oxidation of iron at high temperatures and in an oxygen atmosphere. Large cavities are always found in specimens whose total oxygen content has been brought to that of FeO. The scale thickness of such specimens, along with other evidence, implies that FeO is plastic in the temperature range in which it is stable, while one or both of the higher oxides is relatively rigid. Evidence is presented which indicates that iron is transported to its surrounding scale with little or no body diffusion path; the mechanism involved is not identified. An expression, analogous to the parabolic rate law for scaling of plane specimens, is developed for application to cylindrical geometry. 3.2.3

Analysis of Micro Inclusions in Q195 Steel

2014 ◽  
Vol 540 ◽  
pp. 68-71
Author(s):  
Shuo Ming Wang ◽  
Yan Wang ◽  
Ruo Si Wang
Keyword(s):  
Production Process ◽  
Oxygen Content ◽  
System Analysis ◽  
Steel Production ◽  
Average Content ◽  
Steel Mill ◽  
Total Oxygen ◽  
Total Oxygen Content ◽  
Steel Quality ◽  
Transient Casting

Aimed at the Q195 steel production process in a steel mill, using tracer analysis make system analysis to the process of production and microscopic inclusions content. In the steady casting average T[O] is 117.22ppm, [N] is 22.6ppm, micro inclusions average content is 11.96/mm2, while the average T[O] and [N] in transient casting billet is 161.93ppm and 30.49ppm, micro inclusions averaged content is 16.068/mm2. The total oxygen content in steel on the high side, should strengthen deoxidization. Argon stirring strength is too large, inclusions in casting slab containing tracer element, illustrate the ladle slag, tundish slag, mould protection slag are forming pollution on billet, should reduce the influence of transient casting on the steel quality.

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