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.

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.

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.

Sign in / Sign up

Export Citation Format

Share Document