On the role of granule yield strength for the compactibility of granular solids

The role of pores structure in porous titanium with helical pores was studied. The results showed that porosity of porous titanium depends on diameter of titanium fiber (d1), screw diameter (d2) and screw pitch (d3). With the increase of titanium fiber diameter, the decrease of screw diameter and screw pitch, the porosity of porous titanium decreases. Compressive yield strength and Young’s modulus increase with the decrease of porosity, and the final functional expression of compressive yield strength and Young’s modulus depending on porosity was given.

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Effect of High-Pressure Hydrogen Gas on Fracture of Austenitic Steels

Volume 6: Materials and Fabrication ◽

10.1115/pvp2005-71392 ◽

2005 ◽

Cited By ~ 3

Author(s):

C. San Marchi ◽

D. K. Balch ◽

B. P. Somerday

Keyword(s):

High Pressure ◽

Yield Strength ◽

Hydrogen Gas ◽

Austenitic Steels ◽

Uniaxial Tensile ◽

Low Concentrations ◽

Reduction In Area ◽

Pressure Hydrogen ◽

Assisted Fracture

Applications requiring the containment and transport of hydrogen gas at pressures greater than 70 MPa are anticipated in the evolving hydrogen economy infrastructure. Since hydrogen is known to alter the mechanical properties of materials, data are needed to guide the selection of materials for structural components. The objective of this study is to characterize hydrogen-assisted fracture in two austenitic steels, 21Cr-6Ni-9Mn (21-6-9) and 22Cr-13Ni-5Mn (22-13-5), as well as explore the role of yield strength and small concentrations of ferrite on hydrogen-assisted fracture. The testing methodology involves exposure of uniaxial tensile specimens to high-pressure hydrogen gas in order to precharge the specimens with hydrogen, then subsequently testing the specimens to measure strength and ductility. In all cases, the alloys remained ductile despite precharging to hydrogen concentrations >1 at%, this is substantiated by reduction in area of >50% and fracture surfaces dominated by microvoid coalescence. Low concentrations of ferrite and moderate changes in yield strength did not affect the hydrogen-assisted fracture of 21-6-9 and 22-13-5 respectively.

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Seamless Pipes of High Strength 100 KSI Grade

Volume 3: Materials and Joining; Pipeline Automation and Measurement; Risk and Reliability, Parts A and B ◽

10.1115/ipc2006-10368 ◽

2006 ◽

Author(s):

Ettore Anelli ◽

Andrea Di Schino ◽

Alfonzo Izquierdo ◽

Hector Quintanilla ◽

Giuseppe Cumino ◽

...

Keyword(s):

Chemical Composition ◽

Yield Strength ◽

High Strength ◽

Process Conditions ◽

Production Route ◽

Complex Design ◽

Steel Grades ◽

Set Up ◽

Minimum Yield

A joint industrial program (JIP), termed “Seamless 100 ksi weldable” was launched in order to address the complex design issues of high strength Q&T seamless pipes for ultra deep water applications. The JIP was split in two main phases, the first one devoted to the development and production of seamless pipes, with minimum yield strength of 90 ksi (620 MPa) to 100 ksi (690 MPa), and the second one to evaluate their field weldability. Phase I was recently completed. The role of chemical composition and Q&T process conditions on microstructure and precipitation was analyzed, together with relevant effects on strength and toughness, for both laboratory and industrial steels. The main microstructural features which control the strength-toughness combination of these high strength Q&T steel grades were identified and results were exploited for the set-up of a production route for pipelines and risers. The 100 ksi grade was achieved in 16 mm (0.630 in) and 25 mm (0.980 in) WT pipes. Phase II is in progress.

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