Creep-Rupture Properties of 1.25 Cr–0.5 Mo Steel After Service at 1000 Deg F

1966 ◽  
Vol 88 (3) ◽  
pp. 669-672 ◽  
Author(s):  
T. M. Cullen ◽  
I. A. Rohrig ◽  
J. W. Freeman
Keyword(s):  
Elevated Temperature ◽  
Rupture Strength ◽  
Allowable Stresses ◽  
Reheat Treatment ◽  
Long Time ◽  
Time Strength ◽  
High Level ◽  
Short Time ◽  
Rupture Properties ◽  
Prolonged Service

Specimens of 1.25 Cr–0.5 Mo steel which had been exposed for prolonged times at 1000 F under ASME Boiler and Pressure Vessel Code allowable stresses were rupture tested in order to evaluate the influence of service on subsequent elevated-temperature properties. Specimens were tested as-removed from service and after reheat-treatment. The prolonged service drastically reduced short-time rupture properties but did not have any significant influence on the expected long-time rupture strength. Reheat-treatment restored the short-time strength to a high level.

Short-Time Tensile and Long-Time Creep-Rupture Properties of the HK-40 Alloy and Type 310 Stainless Steel at Temperatures to 2000 F

1967 ◽  
Vol 89 (3) ◽  
pp. 465-478 ◽  
Author(s):  
J. A. VanEcho ◽  
D. B. Roach ◽  
A. M. Hall
Keyword(s):  
Stainless Steel ◽  
Rupture Strength ◽  
Creep Rupture ◽  
Eutectic Carbides ◽  
Heat Resistant Alloy ◽  
310 Stainless Steel ◽  
The Matrix ◽  
Long Time ◽  
Short Time ◽  
Rupture Properties

The short-time tensile properties of the A CI Type HK-40 cast heat-resistant alloy and AISI Type 310 wrought stainless steel were investigated from room temperature to 2000 F. The creep-rupture properties of the HK-40 alloy were studied in the range of 1400 to 2000 F for times long enough to permit extrapolation to 100,000 hr. In addition, the creep-rupture properties of Type 310 were investigated at 1800 to 2000 F, and observations were made of the microstructural changes that occurred in the two materials during creep exposure. The Type 310 material tended to have a higher yield strength and ultimate tensile strength at moderate temperatures than the HK-40; however, from 1200 to 2000 F, the HK-40 was the stronger. The Type 310 was more ductile at all temperatures. The HK-40 displayed about twice the rupture strength of the Type 310 at each test temperature. On the basis of comparable minimum creep rates, the HK-40 showed five to six times the strength of the Type 310 at the same temperature. During exposure at the lower temperatures, chromium carbides precipitated in finely dispersed form in the matrix of the HK-40; isolated islands of sigma phase also tended to form. At high temperatures, the primary eutectic carbides in the HK-40 alloy tended to spheroidize; and both materials absorbed nitrogen from the atmosphere, needles of chromium nitride forming in the matrix.

The Relationship between Maintenance Factor and Lighting Level in Tunnel Lighting

2019 ◽  
pp. 75-84 ◽  
Author(s):  
Mehmet Sait Cengiz
Keyword(s):  
Luminous Flux ◽  
Simulation Program ◽  
The Road ◽  
Long Time ◽  
Computer Environment ◽  
Measurement Devices ◽  
On The Road ◽  
High Level ◽  
Short Time ◽  
The Relationship

Performance decreases in lighting equipment with a high level of contamination have been analysed in this study. Effect of decreases in luminous flux arising from abrasions and usage on tunnel illumination levels has been analysed and results of measurements in real environment and simulation environment have been compared. Calculations, which are complicated and difficult by traditional methods, have been visualized by a simulation program prepared in the computer environment. Results recorded at 60 points by measuring by a luxmeter, which was placed in the middle of 2.266 m2 fields on the road surface into the tunnel, have been compared with simulation results. Thanks to the simulation program used, tunnel lighting measurements would not be necessary, which they take a long time in the physical environment by measurement devices and are carried out by stopping vehicle traffic. Tunnel lighting maintenances, which are complicated and take a long time, will be carried out in a short time and more accurately, and waste of resources could be prevented. It has been determined in the study that more accurate results could be obtained in ergonomic, economic, and using aspects.

Short-time and long-time strength of nitrided niobium alloys

1984 ◽  
Vol 26 (2) ◽  
pp. 156-161
Author(s):  
E. N. Sheftel' ◽  
G. Sh. Usmanova ◽  
V. K. Grigorovich ◽  
V. N. Geminov
Keyword(s):  
Niobium Alloys ◽  
Long Time ◽  
Time Strength ◽  
Short Time

scholarly journals Can B2B Implementation Enhance Competitiveness of Logistic Companies in Coronavirus Economic Recession?

2021 ◽  
Vol 12 (1) ◽  
pp. 1-12
Author(s):  
Libor Šimek ◽  
Václav Cempírek ◽  
Patrik Gross
Keyword(s):  
Economic Crisis ◽  
Market Competition ◽  
Economic Recession ◽  
The Czech Republic ◽  
Market Competitiveness ◽  
Economic Survival ◽  
Long Time ◽  
Implementation Policy ◽  
High Level ◽  
Short Time

Abstract The paper presents recommendations determined to assist logistic companies in conceiving an efficient B2B implementation policy with the aim of enhancing market competitiveness, especially in time of intensified market competition. The research is based on an analysis of the situation in B2B implementation during the period of the 2008-2009 economic crisis, where – on a sample of 229 logistic companies based in the Czech Republic – it ascertains whether the extent of B2B implementation changed over this period. This is done in a short-time (2006 vs. 2010) as well as long-time (extended with 2014 vs. 2018) horizon. Although some conclusions are in contradiction with other authors, they state a high extent of B2B implementation, which even further increased over the above economic crisis and even continued in a longer time horizon following the crisis. The conclusions are then analogically transferred to the present 2020 “coronavirus economic recession” and practicable recommendations are formulated. Being made on a high level of reliability, the recommendations have a potential to serve as an efficient tool ensuring economic “survival” of logistic companies, which is – especially in the field of logistics due to the implemented anti-COVID measures creating new trade barriers – very actual.

Short-Time Tests for Long-Time Endurance

1923 ◽  
Vol 128 (4) ◽  
pp. 264-264
Author(s):  
J. W. Harsch
Keyword(s):  
Long Time ◽  
Short Time

Effect of Vial shaking on Loading Time of Epirubicin into Drug-Eluting Bead

2015 ◽  
Vol 5 (3) ◽  
Author(s):  
Kenji Ikeda ◽  
Yusuke Kawamura ◽  
Masahiro Kobayashi ◽  
Taito Fukushima ◽  
Yushi Sorin ◽  
...  
Keyword(s):  
Antitumor Agent ◽  
Loading Rates ◽  
Vortex Mixer ◽  
Long Time ◽  
Group A ◽  
Drug Eluting ◽  
Large Hepatocellular Carcinoma ◽  
Group B ◽  
Time Required ◽  
Short Time

Background: Although DC Bead has been useful in treatment of multiple and large hepatocellular carcinoma, loading time of doxorubicin into the DC Bead takes a long time of 30-120 minutes. Epirubicin is also used as an antitumor agent together with DC Bead, but its loading efficiency was not sufficiently elucidated. Methods: To shorten loading time of epirubicin into DC Bead (100-300µm, 300-500µm, 500-700µm), we examined the following three methods after mixing the drug: (a) let stand in room temperature, (b) agitated for 30 seconds with Vortex mixer, and (c) sonicated for 30 seconds with ultrasonic cleaner. After loading of epirubicin by each method, supernatant concentration for epirubicin was assayed at 5, 10, 30, 60, and 120 minutes. Results: Epirubicin loading rates for small bead (100-300µm) at 5 minutes were 82.9 % in group a, 93.8% in group b, and 79.9 % in group c. Similarly, medium bead (300-500µm), 40.1% in group a, 65.7% in group b and 45.5% in group c, respectively. In large-sized bead (500-700µm), loaded rates of epirubicin were 38.8% in group a, 59.0% in group b and 48.0% in group c. Agitation of mixture of epirubicin and DC Bead with Vortex mixer significantly shortened the loading time, but sonication did not affect the time required. Microscopic examination did not lead to any morphological change of microspheres in all the methods. Conclusions: Short time of agitation with Vortex mixer reduced the necessary time for loading of epirubicin in every standard of DC Bead.

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