Nucleation of Fatigue in Very Low Oxygen Bearing Steels

2009 ◽  
pp. 124-124-7 ◽  
Author(s):  
TB Lund ◽  
SA Johansson ◽  
LJP Ölund
Keyword(s):  
Low Oxygen ◽  
Bearing Steels

HIF1-α-Mediated Gene Expression Induced by Vitamin B1 Deficiency

2013 ◽  
Vol 83 (3) ◽  
pp. 188-197 ◽  
Author(s):  
Rebecca L. Sweet ◽  
Jason A. Zastre
Keyword(s):  
Gene Expression ◽  
Thiamine Deficiency ◽  
Glucose Transporter ◽  
Neuroblastoma Cell ◽  
Hypoxia Inducible Factor ◽  
Clinical Manifestations ◽  
Vitamin B1 ◽  
Low Oxygen ◽  
Glucose Transporter 1 ◽  
Metabolic Intermediates

It is well established that thiamine deficiency results in an excess of metabolic intermediates such as lactate and pyruvate, which is likely due to insufficient levels of cofactor for the function of thiamine-dependent enzymes. When in excess, both pyruvate and lactate can increase the stabilization of the hypoxia-inducible factor 1-alpha (HIF-1α) transcription factor, resulting in the trans-activation of HIF-1α regulated genes independent of low oxygen, termed pseudo-hypoxia. Therefore, the resulting dysfunction in cellular metabolism and accumulation of pyruvate and lactate during thiamine deficiency may facilitate a pseudo-hypoxic state. In order to investigate the possibility of a transcriptional relationship between hypoxia and thiamine deficiency, we measured alterations in metabolic intermediates, HIF-1α stabilization, and gene expression. We found an increase in intracellular pyruvate and extracellular lactate levels after thiamine deficiency exposure to the neuroblastoma cell line SK-N-BE. Similar to cells exposed to hypoxia, there was a corresponding increase in HIF-1α stabilization and activation of target gene expression during thiamine deficiency, including glucose transporter-1 (GLUT1), vascular endothelial growth factor (VEGF), and aldolase A. Both hypoxia and thiamine deficiency exposure resulted in an increase in the expression of the thiamine transporter SLC19A3. These results indicate thiamine deficiency induces HIF-1α-mediated gene expression similar to that observed in hypoxic stress, and may provide evidence for a central transcriptional response associated with the clinical manifestations of thiamine deficiency.

Influence of Cementite Particle Size Distribution on Machinability and Tool Life of High Carbon Cr-bearing Steels

1998 ◽  
Vol 84 (5) ◽  
pp. 387-392 ◽  
Author(s):  
Takashi INOUE ◽  
Yuzo HOSOI ◽  
Koe NAKAJIMA ◽  
Hiroyuki TAKENAKA ◽  
Tomonori HANYUDA
Keyword(s):  
Particle Size ◽  
Particle Size Distribution ◽  
Size Distribution ◽  
Tool Life ◽  
Cementite Particle ◽  
High Carbon ◽  
Bearing Steels

Bearing Steels for Induction Hardening – Part II

2016 ◽  
Vol 71 (5) ◽  
pp. 218-229 ◽  
Author(s):  
M. Wendel ◽  
F. Hoffmann ◽  
W. Datchary
Keyword(s):  
Induction Hardening ◽  
Bearing Steels

BÖHLER H521

Alloy Digest ◽  
2017 ◽  
Vol 66 (12) ◽  
Keyword(s):  
High Temperature ◽  
Physical Properties ◽  
Tensile Properties ◽  
Heat Treating ◽  
High Temperature Strength ◽  
Low Oxygen ◽  
Good Resistance ◽  
Temperature Performance

Abstract Böhler (or Boehler) H521 is an alloy with superior high-temperature strength, excellent toughness, and with good resistance to oxidizing, nitrogenous, and low oxygen gases. This datasheet provides information on composition, physical properties, hardness, elasticity, and tensile properties as well as creep. It also includes information on high temperature performance as well as forming, heat treating, machining, and joining. Filing Code: SS-1272. Producer or source: Böhler Edelstahl GmbH.

OVAKO 803 J/EN 100CR6

Alloy Digest ◽  
2008 ◽  
Vol 57 (7) ◽  
Keyword(s):  
Fatigue Strength ◽  
North America ◽  
Physical Properties ◽  
Tensile Properties ◽  
Heat Treating ◽  
Cold Forming ◽  
Bearing Steels

Abstract Ovako 100Cr6 comprises a group of through-hardening bearing steels with modification to improve machining, cold forming, and cleanliness for better fatigue strength. This datasheet provides information on composition, physical properties, hardness, elasticity, and tensile properties. It also includes information on casting, forming, and heat treating. Filing Code: SA-582. Producer or source: Ovako North America Inc.

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