Save 20% on select best sellers with code MONSTER24 - Shop The Sale Now
Over the years, the supercritical carbon dioxide (s−CO2) Brayton cycle has been developed as a promising working fluid to replace supercritical water (s−H2O) Rankine cycle. It could be used in various energy systems, including Generation IV nuclear reactors, concentrated solar power plants, fossil fuel thermal power plants, waster heat recovery, etc. due to its merits of high thermal efficiency, simple physical footprint, compact equipment size, high flexibility on operation, simple layout, compact turbomachinery.1
We are unable to complete this action. Please try again at a later time.
If this error continues to occur, please contact AMPP Customer Support for assistance.
Error Message:
Please login to use Standards Credits*
* AMPP Members receive Standards Credits in order to redeem eligible Standards and Reports in the Store
You are not a Member.
AMPP Members enjoy many benefits, including Standards Credits which can be used to redeem eligible Standards and Reports in the Store.
You can visit the Membership Page to learn about the benefits of membership.
You have previously purchased this item.
Go to Downloadable Products in your AMPP Store profile to find this item.
You do not have sufficient Standards Credits to claim this item.
Click on 'ADD TO CART' to purchase this item.
Your Standards Credit(s)
1
Remaining Credits
0
Please review your transaction.
Click on 'REDEEM' to use your Standards Credits to claim this item.
You have successfully redeemed:
Go to Downloadable Products in your AMPP Store Profile to find and download this item.
A lot of oil and gas facilities face corrosion problems because the production fluid contains some corrosive components represented by CO2. Generally, corrosion inhibitors are used in order to mitigate corrosion problems of tubing and pipeline. Imidazoline is known as one of the active ingredients of corrosion inhibitors and widely used in the oil and gas industries. However, imidazoline-type inhibitor is easily hydrolyzed to amide if water mixes into it.
In hydrocarbon production systems, mild steel is overwhelmingly used for the construction of pipelines and tanks for the transmission and storage of crude oil, natural gas, and derived petroleum products. Although mild steel has excellent mechanical properties and low cost, it is susceptible to corrosion attack in typical service environments. Inhibition of internal corrosion is essential for assuring asset integrity of oil and gas transportation pipelines.
Hydrogen sulfide (H2S) is one of the most common gases in the oil and gas industry. Once dissolved in aqueous environments, H2S can induce corrosion damage to carbon steel. It has been proposed that the severity of the damage is related to parameters such as temperature, partial pressure, microstructure of steel, etc.
In a polycrystalline material, the stress distribution on a microscopic scale is not uniform due to the elastic anisotropy and slip systems of constituent crystal grains. This leads to localized high stresses, especially at grain boundaries, when a load is applied to the material. In this paper, this localized stress is called as “microscopic stress”, distinguishing it from that in a homogeneous continuous body.
This work considers wellhead extension joint welds for high-pressure deepwater Gulf of Mexico prospects with a design shut-in tubing pressure (SITP) above 15000 psi. The structural welds joining 75K 8630M low pressure wellhead housing (LPWH) forgings to API 5L Grade X80M PSL 2 conductor casing are expected to be fatigue-sensitive due to water depths approaching 6000 ft. and substantial estimated weight of a 20K BOP stack. Cyclic loading is expected to be from wave‑induced motions (WIM) and vortex‑induced vibration (VIV). The wellhead extension joints extend 10 to 15 ft. above the mudline and will be exposed to seawater as well as cathodic protection when the wellhead is connected to either the BOP stack or the tubing head spool and subsea tree.The present work considered both S-N and fracture mechanics based designs. Fatigue curves such as those in BS (British Standard) 7608 are not yet proven for structural steels with yield strengths in excess of 400 N/mm2 (58 ksi) in the presence of cathodic protection and fatigue crack growth laws such as those in BS 7910 for steels in a marine environment are only applicable to materials with yield strengths less than 600 N/mm2 (87 ksi). Materials in the subject assemblies may have yield strengths in excess of 690 N/mm2 (100 ksi) so both S-N and fatigue crack growth rate (FCGR) testing in a simulated seawater with cathodic protection environment were determined to be appropriate. This paper describes the environmental fatigue testing of welds and the relationship between the test data established fatigue curves and published literature. Tests were performed in a 3.5% NaCl solution at 40 °F with pH adjusted to 8.2 and an applied potential of -1100 mV Ag/AgCl. Frequency scans were conducted in several weld microstructures to assess growth rate sensitivity of each microstructure to cyclic frequency and the fatigue response at the low end of the frequency range was explored in greater detail.
Several mechanisms including Hydrogen-Enhanced Localised Plasticity (HELP) and Hydrogen-Enhanced De-cohesion (HEDE) have been identified as contributing to the hydrogen embrittlement susceptibility of UNS N07718, depending upon microstructural particularities in the material.
Dissimilar metal welds (DMWs) are commonly used in the pressure vessel nozzle to safe-end weld between the ferritic low-alloy steels (LAS) and the austenitic stainless steels (SS), using a nickel-base filler metal. The complex DMW interface consists of different microstructural regions including, for instance, the heat-affected zone (HAZ), carbon-depleted zone (CDZ), carbon build-up at fusion boundary, partially melted zone (PMZ) and carbide precipitation zone. There is still knowledge lacking on the microstructural characteristics of the interface of DMWs upon post-weld heat treatment (PWHT). DMWs are potential concerns regarding the structural integrity of the nuclear power systems. In particular, the LAS/nickel-base alloy weld metal interface is known to develop a local strength mismatch upon PWHT and during long-term ageing. A significant chemical composition gradient, especially in terms of carbon (C) and chromium (Cr) associated with a complex microstructure have been observed to form at the interfaces. The different welding orientation, heat transfer and PWHT can result in different microstructure and mechanical properties.
In this work, the effect of Tungsten on the precipitation kinetics of a 25% Cr SDSS, namely, UNS S32760 was quantified by constructing Time-Temperature-Transformation (TTT) diagrams.
The present paper reports results of analyses that address the influence of physical and modeling variables upon failure projections.