Evaluation of Refinery Corrosion inhibitors★

CORROSION ◽  
1958 ◽  
Vol 14 (12) ◽  
pp. 39-42 ◽  
Author(s):  
A. J. FREEDMAN ◽  
A. DRAVNIEKS

Abstract Since reproduction of refinery operating conditions in the laboratory is difficult, most laboratory testing of refinery corrosion inhibitors has been unreliable. For this reason,, inhibitors for refinery use have been selected mainly on the basis of qualitative field trials. Such tests are expensive and subject to many independent, noncontrollable variables. Frequently, failures of corrosion inhibitors to provide satisfactory protection can be traced to specific environmental factors. Therefore, new laboratory tests for commercial refinery corrosion inhibitors have been developed to simulate closely certain features of actual field conditions. Inhibitors have been evaluated for corrosion protection in light naphtha condensers, distillation towers, special high temperature locations, high velocity service, narrow crevices, and for impingement attack. These test data show conclusively that no single corrosion inhibitor can be expected to provide satisfactory corrosion protection in all refinery locations. Plant results obtained with electrical resistance corrosion probes corroborate the laboratory evaluations. 5.8.1

Author(s):  
Robert A. Ainsworth

Detailed analysis of dissimilar metal welds (DMWs) is difficult and the accuracy of the results is often limited by the availability of materials data and knowledge of operating conditions. There are few design or assessment procedures that explicitly take account of the presence of DMWs under high temperature creep and fatigue conditions. One that does is the UK R5 procedure, which provides a simplified assessment approach based on laboratory testing and stress analysis supported by service experience. This paper briefly summarises the R5 approach. Then, more recent work on performance of DMWs operating at high temperature and issues for development of analysis methods is discussed.


Author(s):  
M.J. Kanda ◽  
T.R. Stacey

SYNOPSIS Thin spray-on liners (TSLs) have been used as sealants and rock support in tunnels for over 25 years. Laboratory tests have indicated satisfactory properties that can provide adequate strength, adhesion, toughness, and elasticity as part of rock support systems in mining excavations. These characteristics are, however, not always demonstrated in practice, when mine environmental conditions do not correspond with laboratory environmental conditions. The shortcomings of TSLs experienced in the mining industry have raised concerns, resulting in scepticism from some operators regarding their utilization. The research described in this paper aims to investigate TSL performance in environmental conditions similar to those experienced in mines. Brazilian indirect tensile (BIT) specimens were prepared from precast shotcrete and coated with TSLs. The specimens were then exposed to different environmental conditions for up to 112 days before BIT testing under various conditions: laboratory room temperature and humidity; saturated room temperature; and combined saturated and high temperature (50°C). Additional uncoated shotcrete and TSL BIT specimens were prepared for comparison purposes. The results of the BIT tests showed that environmental conditions have a significant influence on the tensile strength enhancement of shotcrete by TSLs. Water-based TSLs are most likely to be suitable for high humidity environments, although their performance decreases at higher temperatures. Numerical modelling of TSL-coated BIT samples confirms the potential limitations of designing TSL support based only on laboratory testing carried out under room conditions. Keywords: thin spray-on liner, Brazilian indirect tensile (BIT) test, TSL performance, environmental conditions, humidity, high temperature.


2020 ◽  
pp. 10-21
Author(s):  
V. G. Babashov ◽  
◽  
N. M. Varrik ◽  

The emergence of new types of space and aviation technology necessitates the development of new types of thermal protection systems capable of operating at high temperature and long operating times. There are several types of thermal protection systems for different operating conditions: active thermal protection systems using forced supply of coolant to the protected surface, passive thermal protection systems using materials with low thermal conductivity without additional heat removal, high-temperature systems, which are simultaneously elements of the bearing structure and provide thermal protection, ablation materials. Heat protection systems in the form of rigid tiles and flexible panels, felt and mats are most common kind of heat protecting systems. This article examines the trends of development of flexible reusable heat protection systems intended for passive protection of aircraft structural structures from overheating.


Alloy Digest ◽  
1964 ◽  
Vol 13 (5) ◽  

Abstract Unitemp-HX is a nickel-base material recommended for high temperature applications. It has outstanding oxidation resistance at high temperatures under most operating conditions, and good high-temperature strength. This datasheet provides information on composition, physical properties, hardness, elasticity, and tensile properties as well as fracture toughness and creep. It also includes information on low and high temperature performance, and corrosion resistance as well as forming, heat treating, machining, joining, and surface treatment. Filing Code: Ni-91. Producer or source: Universal Cyclops Steel Corporation.


Alloy Digest ◽  
1954 ◽  
Vol 3 (12) ◽  

Abstract HASTELLOY Alloy X is a nickel-chromium-iron-molybdenum alloy recommended for high-temperature applications. It has outstanding oxidation resistance at high temperatures under most operating conditions, and good high-temperature strength. This datasheet provides information on composition, physical properties, and tensile properties as well as creep. It also includes information on forming, heat treating, and machining. Filing Code: Ni-14. Producer or source: Haynes Stellite Company.


Alloy Digest ◽  
2007 ◽  
Vol 56 (4) ◽  

Abstract AK Steel 409 Ultra Form was created for applications needing oxidation or corrosion protection beyond the capability of carbon steel and some coated steels. AK Steel 409 Ultra Form is more formable than standard Type 409 stainless steel and is particularly suitable for parts requiring more complex shapes and improved weldability. Examples of applications include automotive exhaust tubing and stampings. This datasheet provides information on physical properties, hardness, elasticity, and tensile properties as well as deformation. It also includes information on high temperature performance as well as forming and joining. Filing Code: SS-990. Producer or source: AK Steel, Butler Operations.


Alloy Digest ◽  
1997 ◽  
Vol 46 (4) ◽  

Abstract Remanit 4306 is a low-carbon chromium nickel austenitic stainless steel that is superior in corrosion resistance to type 302 (see Alloy Digest SS-99, revised September 1998). Due to its low carbon content, Remanit 4306 is intergranular corrosion resistant under continuous operating conditions up to 350 C (652 F). This grade is particular suitable for high degrees of cold working and for sequential drawing. This datasheet provides information on composition, physical properties, elasticity, and tensile properties. It also includes information on high temperature performance and corrosion resistance as well as forming, heat treating, and joining. Filing Code: SS-679. Producer or source: Thyssen Stahl AG.


2019 ◽  
pp. 43-48
Author(s):  
Ben Nengjun ◽  
Zhou Pengfei ◽  
Oleksandr Labartkava ◽  
Mykhailo Samokhin

This work involves an analysis of high-chromium high-temperature deformable wieldable nickel alloys for use in GTE repair assemblies. It is shown that the alloys EP868 (VZh98) and Haynes 230 can be used in welded assemblies with an operating temperature of 800-1100 °C. The alloys Nimonic 81, Nimonic 91, IN 935, IN 939, and Nicrotan 2100 GT also have a high potential for use in welded assemblies. They are characterized by a combination of good weldability, high-temperature strength, and resistance to scaling. There have been conducted studies on high-temperature salt corrosion of model nickel alloys. They allowed establishing the patterns of the impact of base metal alloying with chromium, aluminum, titanium, cobalt, tungsten, molybdenum, niobium, tantalum and rare earth metals on the critical temperature of the start of salt corrosion Tcor and the alloy mass loss. It has been established that alloys with a moderate concentration (13-16%) of chromium can possess satisfactory hightemperature corrosion resistance (HTC resistance) under the operating conditions of ship GTE. The HTC resistance of CrAl-Ti alloys improves upon reaching the ratio Ti/Al ˃ 1. Meanwhile, the ratio Ti/Al ˂ 1 promotes the formation of corrosion products with low protective properties. The positive effect of tantalum on the HTC resistance of alloys is manifested at higher test temperatures than that of titanium, and the total content of molybdenum and tungsten in alloys is limited by the condition 8Mo2 – 2W2 = 89. The presence of refractory elements stabilizes the strengthening phase and prevents formation of the ɳ-phase. However, their excess promotes formation of the embrittling topologically close packed (TCP) phases and boundary carbides of an unfavorable morphology. Based on the studies of the HTC resistance, there has been identified a class of model high-temperature corrosionresistant nickel alloys with a moderate or high chromium content (30%), Ti/Al ˃ 1, and a balanced content of refractory and rare-earth elements.


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