Creep Properties of Steels Utilized in High-pressure and High-temperature Superheater and Steam Pipe Practice. Part II: 0·5 per cent Molybdenum Steels

1945 ◽  
Vol 153 (1) ◽  
pp. 181-192 ◽  
Author(s):  
H. J. Tapsell ◽  
R. W. Ridley
Keyword(s):  
High Pressure ◽  
High Temperature ◽  
Carbon Steels ◽  
Creep Properties ◽  
Superheater Tube ◽  
Steam Pipe

This report deals with the creep properties of carbon-molybdenum steels in the form of a superheater header, superheater tube, and steam pipe manufactured for service at temperatures above about 450 deg. C. (842 deg. F.). The investigation was carried out in a similar manner to that described in Part I (Proceedings, 1944, vol. 151, p. 54) which dealt with carbon steels and, as in the former case, the object was to obtain data for the estimation of the stress-temperature relationships for from 0·1 to 0·5 per cent creep in various periods up to 100,000 hours. It is considered that the data provide a satisfactory basis for design.

Creep Properties of Steels Utilized in High-Pressure and High-Temperature Superheater and Steam Pipe Practice. Part I: Carbon Steels

1944 ◽  
Vol 151 (1) ◽  
pp. 54-62 ◽  
Author(s):  
H. J. Tapsell
Keyword(s):  
High Pressure ◽  
High Temperature ◽  
Carbon Steels ◽  
Creep Properties ◽  
Molybdenum Steel ◽  
Steam Pipe ◽  
Steam Pipes ◽  
Sufficient Precision ◽  
Creep Strains

This report deals with the creep properties of carbon steels used in superheater headers, superheater tubes, and steam pipes for service at temperatures up to about 480 deg. C. The object of the investigation was to obtain data for the estimation of the stress-temperature relationships for specific creep strains of 0·1–0·5 per cent to occur in 100,000 hours, and these have been obtained with sufficient precision to warrant their acceptance for practical purposes. Similar components in molybdenum steel are under investigation.

Failure Analysis of T91 Finishing Superheater Tube Bursting for Improper Initial Microstructure and their Life Evaluation

2012 ◽  
Vol 557-559 ◽  
pp. 187-190
Author(s):  
Jie Ouyang ◽  
Xue Xia Xu ◽  
Yan Ting Feng ◽  
Xiao Guang Niu ◽  
Guang Zong Yan ◽  
...  
Keyword(s):  
Heat Treatment ◽  
High Temperature ◽  
Failure Analysis ◽  
Standard Heat Treatment ◽  
Creep Properties ◽  
Initial Microstructure ◽  
Superheater Tube ◽  
Life Evaluation ◽  
Creep Rupture Test ◽  
Test Result

The failure analysis was performed for T91 finishing superheater bursting tube. It is concluded that improper initial microstructure resulted from non-standard heat treatment contributes to poor creep properties at high temperature and subsequent tube bursting. In addition, life evaluation was carried out on the basis of creep-rupture test result of experimental steel with similar improper microstructure. It is in accordance with the practical condition and provides significant guidance for safety and operation supervision.

Corrosion Behavior of Novel Cr2MoNbTi Pipeline Steel in CO2 Environment

2012 ◽  
Author(s):  
Wenliang Zhang ◽  
Lining Xu ◽  
Shaoqiang Guo ◽  
Lei Zhang ◽  
Minxu Lu ◽  
...  
Keyword(s):  
High Pressure ◽  
High Temperature ◽  
Corrosion Behavior ◽  
Oil And Gas ◽  
Pipeline Steel ◽  
Oil And Gas Industry ◽  
Carbon Steels ◽  
Co2 Corrosion ◽  
Uniform Corrosion ◽  
High Temperature High Pressure

CO2 corrosion is frequently encountered in oil and gas industry. The search for new sources of oil and gas has pushed the operational activities to harsher environment and this requires new tubing and pipeline materials which can endure tough circumstances. Low alloy steel containing Chromium, which fills the gap between carbon steels and corrosion resistant alloys in terms of cost and corrosion resistance, has aroused significant interest from steel enterprises and scholars. At present, these studies mainly focus on 3%–5%Cr steel, and little study concerns the 2%Cr steel, which is more economic and weldable. In this paper, novel Cr2MoNbTi steel was developed and the microstructure and mechanical properties were studied. Corrosion behavior of the Cr2MoNbTi steel immersed in the CO2-containing solutions, which corresponded to the environment of bottom-of-line corrosion (BLC), was studied using high temperature-high pressure autoclave. In addition, dynamic high temperature-high pressure condensation autoclave was employed to simulate the top-of-line corrosion (TLC) environment and the corrosion behavior of the Cr2MoNbTi steel under wet gas environment was investigated. The composition and morphology of the corrosion scale were characterized by energy dispersive spectroscopy and scanning electron microscopy analyses. The results show that the Cr2MoNbTi steel exhibited uniform corrosion and presented good resistance to CO2 corrosion compared with X65 pipeline steel.

Microstructural Study of Diamond Deformed Under High Pressure and Temperature

1985 ◽  
Vol 43 ◽  
pp. 230-231
Author(s):  
E. F. Koch
Keyword(s):  
High Pressure ◽  
High Temperature ◽  
Lattice Structure ◽  
Diamond Particle ◽  
Polycrystalline Diamond ◽  
Sintering Process ◽  
Ion Milling ◽  
Sintered Compact ◽  
Transmission Electron ◽  
High Pressure Sintering

Because of the extremely rigid lattice structure of diamond, generating new dislocations or moving existing dislocations in diamond by applying mechanical stress at ambient temperature is very difficult. Analysis of portions of diamonds deformed under bending stress at elevated temperature has shown that diamond deforms plastically under suitable conditions and that its primary slip systems are on the ﹛111﹜ planes. Plastic deformation in diamond is more commonly observed during the high temperature - high pressure sintering process used to make diamond compacts. The pressure and temperature conditions in the sintering presses are sufficiently high that many diamond grains in the sintered compact show deformed microtructures.In this report commercially available polycrystalline diamond discs for rock cutting applications were analyzed to study the deformation substructures in the diamond grains using transmission electron microscopy. An individual diamond particle can be plastically deformed in a high pressure apparatus at high temperature, but it is nearly impossible to prepare such a particle for TEM observation, since any medium in which the diamond is mounted wears away faster than the diamond during ion milling and the diamond is lost.

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