Comparison of 15-5PH Stainless Steel Type 1 versus Type 2 Fatigue Data for Aircraft Primary Structural Elements

2015 ◽  
Author(s):  
Douglas Leicht ◽  
Kirk Olsen
Keyword(s):  
Stainless Steel ◽  
Structural Elements ◽  
Steel Type ◽  
Fatigue Data

scholarly journals Improvement of Dynamic Buckling Behavior of Intermediate Aluminized Stainless Steel Columns

2017 ◽  
Vol 13 (1) ◽  
pp. 26-41
Author(s):  
Ahmed Naif Al-Khazraji ◽  
Samir Ali Al-Rabii ◽  
Hameed Shamkhi Al-Khazaali
Keyword(s):  
Stainless Steel ◽  
Dynamic Compression ◽  
Dynamic Buckling ◽  
Experimental Results ◽  
Combined Loading ◽  
Buckling Behavior ◽  
Reduced Modulus ◽  
Bending Loading

This paper experimentally investigated the dynamic buckling behavior of AISI 303 stainless steel aluminized and as received intermediate columns.  Twenty seven specimens without aluminizing (type 1) and 75 specimens with hot-dip aluminizing at different aluminizing conditions of dipping temperature and dipping time (type 2), were tested under dynamic compression loading (compression and torsion), dynamic bending loading (bending and torsion), and under dynamic combined loading (compression, bending, and torsion) by using a rotating buckling test machine. The experimental results werecompared with tangent modulus theory, reduced modulus theory, and Perry Robertson interaction formula. Reduced modulus was formulated to circular cross-section for the specimens of type (1).The experimental results obtained showed an advantageous influence of hot-dip aluminizing treatment on the dynamic buckling behavior of AISI 303 stainless steel intermediate columns. The improvements based on the average value of critical stress were19.4 % for intermediate columns type (2) compared with columns type (1) under dynamic compression loading, 8.7 % for intermediate columns type (2) compared with columns type (1) under dynamic bending loading, and 16.5 % for intermediate columns type (2) compared with columns type (1) under dynamic combined loading.

scholarly journals Behavior of triplex steel containing different aluminum content

2017 ◽  
Vol 17 (1) ◽  
pp. 34-43 ◽  
Author(s):  
M. I. Masoud ◽  
M. Tashkandi ◽  
J. Al-Jarrah ◽  
A. I. Z. Farahat
Keyword(s):  
Mechanical Properties ◽  
Aluminum Content ◽  
Hot Forging ◽  
Air Cooling ◽  
Scanning Electron Micrographs ◽  
Maximum Hardness ◽  
Steel Type ◽  
Scanning Electron

Abstract Medium-carbon alloy steels containing different aluminum contents were hot forged by 95% reduction at 1200°C followed by air cooling. Optical and scanning electron microscopes were used to investigate the morphologies of the different phases present. An austentizing process followed by water quenching (after hot forging) was carried out to obtain different hardness values. The intensity of the different planes was investigated using X-ray diffraction. The mechanical properties were characterized using tensile and hardness tests. Optical and scanning electron micrographs revealed a great effect of aluminum content on the steel properties. A matrix of bainite and pearlite and traces of ferrite was revealed for hot forged steel type 1 containing 1% Al. Steel type 2 containing 2% Al showed a matrix of pearlite and ferrite with the absence of bainite. The hardness increased with increasing the temperature to a maximum value then decreased for steel containing 1 and 2% aluminum. After austentizing at 925°C, the maximum hardness of 649Hv was recorded for hot forged steel type 2 of 2% aluminum, while steel type 1 of 1% aluminum showed a maximum hardness of 531Hv after austentizing at 1000°C. Thus, the maximum hardness of hot forged steels decreased with increasing aluminum content. In addition, the maximum tensile and yield strength were decreased by increasing the aluminum content in the steel. The changes in microstructure and mechanical properties of these steels could be explained by the effect of aluminum as a ferrite forming element.

Type 2 Diabetes Overtakes Type 1 in Hispanic Girls

2008 ◽  
Vol 38 (15) ◽  
pp. 18
Author(s):  
SHERRY BOSCHERT
Keyword(s):  
Type 2 Diabetes

Molecular analysis of FVIII gene in severe HA patients of Costa Rica

2010 ◽  
Vol 30 (S 01) ◽  
pp. S150-S152
Author(s):  
G. Jiménez-Cruz ◽  
M. Mendez ◽  
P. Chaverri ◽  
P. Alvarado ◽  
W. Schröder ◽  
...  
Keyword(s):  
Factor Viii ◽  
Coagulation Factor ◽  
Costa Rican ◽  
Factor Viii Gene ◽  
Intron 22 Inversion ◽  
Intron 1 ◽  
Polymerase Chain ◽  
Inversion Analysis

SummaryHaemophilia A (HA) is X-chromosome linked bleeding disorders caused by deficiency of the coagulation factor VIII (FVIII). It is caused by FVIII gene intron 22 inversion (Inv22) in approximately 45% and by intron 1 inversion (Inv1) in 5% of the patients. Both inversions occur as a result of intrachromosomal recombination between homologous regions, in intron 1 or 22 and their extragenic copy located telomeric to the FVIII gene. The aim of this study was to analyze the presence of these mutations in 25 HA Costa Rican families. Patients, methods: We studied 34 HA patients and 110 unrelated obligate members and possible carriers for the presence of Inv22or Inv1. Standard analyses of the factor VIII gene were used incl. Southern blot and long-range polymerase chain reaction for inversion analysis. Results: We found altered Inv22 restriction profiles in 21 patients and 37 carriers. It was found type 1 and type 2 of the inversion of Inv22. During the screening for Inv1 among the HA patient, who were Inv22 negative, we did not found this mutation. Discussion: Our data highlight the importance of the analysis of Inv22 for their association with development of inhibitors in the HA patients and we are continuous searching of Inv1 mutation. This knowledge represents a step for genetic counseling and prevention of the inhibitor development.

Polymorphisms of the Plasminogen Activator Inhibitor- 1 Gene in Type 1 and Type 2 Diabetes, and in Patients with Diabetic Retinopathy

1994 ◽  
Vol 71 (06) ◽  
pp. 731-736 ◽  
Author(s):  
M W Mansfield ◽  
M H Stickland ◽  
A M Carter ◽  
P J Grant
Keyword(s):  
Diabetic Retinopathy ◽  
Plasminogen Activator Inhibitor ◽  
Allelic Frequency ◽  
Repeat Sequence ◽  
Dinucleotide Repeat ◽  
Plasminogen Activator Inhibitor 1 ◽  
The Difference ◽  
Pai 1

SummaryTo identify whether genotype contributes to the difference in PAI-1 levels in type 1 and type 2 diabetic subjects and whether genotype relates to the development of retinopathy, a Hind III restriction fragment length polymorphism and two dinucleotide repeat polymorphisms were studied. In 519 Caucasian diabetic subjects (192 type 1, 327 type 2) and 123 Caucasian control subjects there were no differences in the frequency of the Hind III restriction alleles (type 1 vs type 2 vs control: allele 1 0.397 vs 0.420 vs 0.448; allele 2 0.603 vs 0.580 vs 0.552) nor in the allelic frequency at either dinucleotide repeat sequence. In 86 subjects with no retinopathy at 15 years or more from diagnosis of diabetes and 190 subjects with diabetic retinopathy there was no difference in the frequency of Hind III restriction alleles (retinopathy present vs retinopathy absent: allele 1 0.400 vs 0.467; allele 2 0.600 vs 0.533) nor in the allelic frequencies at either dinucleotide repeat sequence. The results indicate that there is no or minimal influence of the PAI-1 gene on either PAI-1 levels or the development of diabetic retinopathy in patients with diabetes mellitus.

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