Showing papers on "Carbon steel published in 1993"
TL;DR: In this paper, the authors studied the corrosion of mild steel under completely anaerobic conditions in the presence of a mixed population biofilm, including sulfate-reducing bacteria (SRB), in a continuous flow system.
Abstract: Corrosion of mild steel under completely anaerobic conditions in the presence of a mixed population biofilm, including sulfate-reducing bacteria (SRB), has been studied in a continuous flow system. The closed channel flow reactor was continuously fed with low concentration substrate at different dilution rates that influenced biofilm accumulation. No direct correlation was observed between corrosion and SRB activity in the absence of ferrous iron. Furthermore, corrosion of mild steel in the SRB environment was determined by the nature of the metal and environmental conditions such as dissolved iron concentration. When formation of an iron sulfide film on mild steel was prevented before the biofilm accumulated, the metal surface retained its scratch lines after a 21-day experiment (SRB at 2.6 × 109/cm2). However, when the iron sulfide film was formed before the accumulation of biofilm, visible localized corrosion appeared after 14 days and increased up to 21 days. Intergranular and pitting attack ...
146 citations
TL;DR: In this article, a direct current polarization (DCP) was used to degrade carbon steel components in sulfur-containing environments, which is a major concern in oil and gas production, and the results showed that the DCP was effective in reducing carbon steel degradation.
Abstract: The chemical degradation of carbon steel components in sulfur-containing environments is a major concern in oil and gas production. In a previous study, a direct current (DC) polarization ...
104 citations
TL;DR: The relationship of laboratory fluid flow corrosion test techniques to flow-accelerated corrosion in field applications and the parameters required to apply laboratory data effectively in the field were studied in this paper, where single-phase, aqueous, sweet corrosion of steel in turbulent pipe flow (12.7 mm and 25.4 mm diam) was correlated to corrosion in jet impingement and rotating cylinder tests.
Abstract: The relationship of laboratory fluid flow corrosion test techniques to flow-accelerated corrosion in field applications and the parameters required to apply laboratory data effectively in the field were studied. Single-phase, aqueous, sweet corrosion of steel in turbulent pipe flow (12.7 mm and 25.4 mm diam) was correlated to corrosion in jet impingement and rotating cylinder tests. All tests were conducted simultaneously, using the same test fluid to minimize environmental variables and to allow a direct, realistic comparison of test methods. Rotating cylinder electrode corrosion rates did not correlate with pipe flow based on wall shear stress or mass transfer for flow-accelerated corrosion of carbon (C) steel in the environment studied. Jet impingement corrosion rates for the test ring at r/r0=3 correlated with pipe flow based on wall shear stress. The general equation for flow-accelerated corrosion of C steel under turbulent flow conditions in this environment was expressed as: Rcorr = a τwb ...
101 citations
TL;DR: In this paper, longitudinal and transverse internal friction values for low carbon steel and stainless steel were simultaneously measured over a temperature range 300-1500 K, by an ultrasonic pulse sing-around method.
Abstract: Elastic (Young, shear and bulk moduli, Poisson's ratio and Lame parameter), longitudinal and transverse internal friction values for low carbon steel and stainless steel were simultaneously measured over a temperature range 300-1500 K, by an ultrasonic pulse sing-around method. These elastic moduli decrease and Poisson's ratio increases with increasing temperature, suggesting activation of shear mode in a high temperature region. Longitudinal and transverse internal frictions are sensitive to recrystalization, and to α(ferritic)/γ(austenitic) phase transition and solution of precipitated carbide phases into the austenitic matrix, respectively. A relaxation peak with an apparent activation energy of 0.97 eV was observed at around 610 K for the carbon steel.
93 citations
TL;DR: A new type of passivity in carbon (C) steels that occurs in the correct range of carbon dioxide (CO2), bicarbonate (HCO3−), sodium chloride (NaCl), and potential was discovered as discussed by the authors.
Abstract: A new type of passivity in carbon (C) steels that occurs in the correct range of carbon dioxide (CO2), bicarbonate (HCO3−), sodium chloride (NaCl), and potential was discovered. C steels n...
75 citations
TL;DR: In this article, chemical and structural properties of the rust formed by corrosion of steel in aqueous solutions were studied by X-ray diffraction and Fourier transform infrared (FT-IR) spectroscopy.
Abstract: Chemical and structural properties of the rust formed by corrosion of steel in aqueous solutions were studied by X-ray diffraction and Fourier transform infrared (FT-IR) spectroscopy. The corrosion products of steel were generated in aqueous solutions of different electrolyte compositions at room temperature (20 °C) or in an autoclave at 120 °C. X-ray diffraction analysis showed the presence of different oxide phases in the rust, such as lepidocrocite, magnetite, ferrihydrite, goethite and haematite. In all samples, the presence of an amorphous fraction was detected. Ferrihydrite was detected only in the rust samples formed at 120 °C, The characteristic properties of the FT-IR spectrum of the ferrihydrite component in the rust were investigated. Phase compositions of the corrosion products depended on the formation temperature and the electrolyte composition of the aqueous solutions. The influence of chloride, nitrate or sulphate anions on the phase composition of the rust is discussed.
62 citations
TL;DR: In this paper, the authors reported a dramatic increase in tensile ductility (from 13 to 21 to 60 pct) and a decrease in delamination tendency at the UHCS-brass interfaces as layer thickness was decreased.
Abstract: Laminated metal composites containing equal volume percentage of ultrahigh carbon steel (UHCS) and brass were prepared in three different layer thicknesses (750, 200, and 50 μm) by press- bonding and rolling at elevated temperature and were tensile tested at ambient temperature. A dramatic increase in tensile ductility (from 13 to 21 to 60 pct) and a decrease in delamination tendency at the UHCS-brass interfaces were observed as the layer thickness was decreased. The layer thickness effect on ductility is attributed to residual stress whose influence on delamination is decreased as the layer thickness is decreased. Suppression of delamination inhibits neck for- mation in the UHCS layers, allowing for extended uniform plasticity. For a given layer thick- ness, the tensile ductility decreases as the ratio of hardness of component layers is increased.
49 citations
TL;DR: In this paper, the quantitative relations between the corrosion rate (in terms of the corrosion current density, Icorr) of steel in concrete and the electrolyte supply was studied.
Abstract: The quantitative relations between the corrosion rate (in terms of the corrosion current density, Icorr) of steel in concrete and the electrolyte supply was studied. The degree of pore saturation of concrete determined the type of natural control of the corrosion kinetics of the embedded steel. Corrosion of steel in atmosphere and in concrete in an active state conformed to a semi-logarithmic relationship between Icorr and the relative humidity (RH) of the atmosphere or the degree of pore saturation of the concrete. The latter variable dictated resistivity of the concrete. However, once corrosion at a steel-concrete interface started, it was found that the concrete cover could be detrimental to the corrosion process of the embedded steel. The porous nature of the concrete resulted in longer wetting times than bare steel surfaces.
44 citations
TL;DR: A modified Crussard-Jaoul analysis has been employed to describe the strain hardening behavior (the ln(dσ/de) versus In σ curves) of a 1020 dual-phase steel as discussed by the authors.
Abstract: A modified Crussard-Jaoul analysis has been employed to describe the strain hardening behaviour (the ln(dσ/de) versus In σ curves) of a 1020 dual-phase steel with quenching and quenching+tempering treatments and with different predeformations, which demonstrated that this dual-phase steel exhibits two stages of strain-hardening in the range of plastic deformation. An analysis of instability for dual-phase steel is also presented and the relationship between the maximum uniform strain and the material parameters is proposed, which shows good agreement with the experimental results for the present 1020 dual-phase steel and other dual-phase steels.
43 citations
TL;DR: In this paper, the effects of fluid flow on the corrosion resistance of oil well materials in environments containing CO2 were studied using two experimental techniques: weight loss measurements and a large flow loop that could attain a maximum liquid flow rate of 20 m/s.
Abstract: Effects of fluid flow on the corrosion resistance of oil well materials in environments containing CO2 were studied using two experimental techniques. One method utilized weight loss measurements and a large flow loop that could attain a maximum liquid flow rate of 20 m/s. The other utilized electrochemical measurements with rotating electrodes. The corrosion rate of carbon steel measured in the flow loop increased with the flow rate. But, the corrosion rate of 13Cr martensitic stainless steel (UNS S42000) increased to 0.5 mm/y to become constant at the flow rate of 3 m/s. Corrosion rates were obtained from the electrochemical data using the Stern-Geary method, as a function of the speed of rotation. The results obtained by the two experimental methods were compared by hydrodynamic analysis. Using the similarity solutions obtained for mass transfer with pipe flow and the rotating electrode, the rotating velocity was converted to the equivalent velocity in the pipe. On that basis, the corrosion ra...
40 citations
TL;DR: In this article, a thin film multilayered TiN/Ti composites are investigated as a possible alternative for protective coating of steels, and a discussion is presented on the influence of the multilayer parameters on this beneficial effect.
Abstract: Thin film multilayered TiN/Ti composites are investigated as a possible alternative for protective coating of steels. Corrosion tests based in cyclovoltametry made in a buffered acetic acid solution reveal that multilayered coatings of this kind with total thickness of 0.5 μm perform as well as 3 μm single layered coatings. A discussion is presented on the influence of the multilayer parameters on this beneficial effect.
TL;DR: In this article, the corrosion inhibition of carbon steel by OH− and MoO42− was studied in LiBr solutions of 1 −23 m (mol kg−1-H2O) at 120 and 160°C.
TL;DR: The aqueous CrO3NaOH-picric acid solution, heated to 120-130°C, will reveal prior-austenite grain boundaries in carbon steels, alloy steels (including alloys with more than 1% Si), and high-carbon, high-chromium steels with different microstructures as mentioned in this paper.
TL;DR: In this paper, the corrosion of carbon steel was studied in various LiBr solutions of 1−25 m (mol kg−1-H2O) at 100−160°C in relation to absorption refrigeration and heat pump systems.
TL;DR: In this paper, the electrochemical impedance technique was applied to study the corrosive and electrochemical activity at the metal/rust interface in connection with the application of protective treatments to rusted steel.
TL;DR: In this article, a depth profile of carbon steel was obtained using Auger electron spectroscopy (AES) and the influence of changes in the water composition using model solutions in contact with carbon steel on the formation and growth rate of the film was studied.
Patent•
17 May 1993TL;DR: In this article, a steel containing ferrite and carbide phases is heated to a soaking temperature approximately 50° C. above the A1 transformation temperature, and then cooling to a predetermined temperature within predetermined limits of cooling rate or transformation temperature.
Abstract: Ultrahigh carbon steels with superplastic properties are produced by heating a steel containing ferrite and carbide phases to a soaking temperature approximately 50° C. above the A1 transformation temperature, soaking the steel above the A1 temperature for a sufficient time that the major portion of the carbides dissolve into the austenite matrix, and then cooling the steel in a controlled manner within predetermined limits of cooling rate or transformation temperature, to obtain a steel having substantially spheroidal carbides. New alloy compositions contain aluminum and solute additions which promote the formation of a fine grain size and improve the resistance of the carbides to coarsening at the forming temperature.
TL;DR: In this article, a constant extension rate test was performed on smooth and notched wire specimens in deaerated Ca(OH)2 solutions as a function of potential, [Cl−], pH, and precharging time.
Abstract: Corrosion of prestressing steel in concrete has become a major technological problem in highways, buildings, and pipeline structures. While cathodic protection is recognized as an appropriate technique to mitigate corrosion of reinforcing steel in concrete, the possibility of environmental cracking (hydrogen embrittlement) in the case of prestressing tendon has limited application to this usage. To establish the appropriateness of cathodic protection for prestressing steel, constant extension rate testing was pertormed on smooth and notched wire specimens in deaerated Ca(OH)2 solutions as a function of potential, [Cl−], pH, and precharging time. Results indicated potential is the most important of these variables, and a threshold value of −0.90 VSCE was identified below which embrittlement is enhanced. Notched specimens, which may best simulate the geometry of corroded tendon, particularly were susceptible when compared to smooth tendon. Failure of some tendons in this condition could occur upon ...
TL;DR: In this article, a computer simulation system was developed to estimate the heat-affected zone (HAZ) of carbon steel in surface grinding process, which is usually generated by solid state phase transformation caused by the grinding temperature.
TL;DR: Abrasion tests were conducted at various loads and wheel speeds using crushed silica sand as the abrasive medium, and the results showed that the increase in bulk hardness of the steel specimen caused a linear increase in wear resistance.
Patent•
22 Jun 1993TL;DR: In this paper, a cold-rolled steel sheet and a hot dip zinc-coated cold rolled steel sheet are presented, which are shown to have high paint bake hardenability and non-aging properties.
Abstract: The present invention provides a cold rolled steel sheet and a hot dip zinc-coated cold rolled steel sheet excellent in paint bake hardenability, non-aging properties and formability, and a process for producing the same. In the present invention, an extremely low carbon steel or extremely low carbon steel containing at least one element selected from the group consisting of Ti and Nb is used as a base steel, and Mn and Cr are positively added thereto, whereby the resultant steel has a mixed structure after annealing. Accordingly, there can be obtained a steel sheet having both a high paint bake hardenability and non-aging properties, and being excellent in formability such as an average r-value (deep drawability). With regard to the paint bake hardenability, the present invention may provide a cold rolled steel sheet and a hot dip zinc-coated cold rolled steel sheet to which paint bake hardening may be optionally imparted in an amount as large as about 10 kgf/mm2 and which also have non-aging properties.
TL;DR: In this article, a 0.34% carbon steel was subjected to hot working (800 − 1100°C) by Gleeble compression to 0.7 strain at strain rates of 0.1 − 8 s−1.
Journal Article•
TL;DR: In this paper, spot welds were produced using a high-strength cold-rolled sheet steel 0.08in. (1.9mm) thick and the welding parameters were systematically varied to examine their effects on nugget formation, microstructure, and mechanical properties.
Abstract: Spot welds were produced using a high-strength cold-rolled sheet steel 0.08-in. (1.9-mm) thick. The welding parameters were systematically varied to examine their effects on nugget formation, microstructure, and mechanical properties. Following welding, several spot welds were cross-sectioned and mechanically polished for metallographic examination. Other spot welds were submitted to shear tensile tests. It is observed that welding current and weld time are more significant parameters than applied electrode force in affecting expulsion. In all the spot welds examined, it was found that solidification cracking could be reduced but not eliminated, and it was observed that for this particular steel, a weld cycle of 18 and a holding cycle of 15 resulted in the least amount of solidification cracking. Nugget displacement to one side of the faying surface, also known as 'stuck weld,' was observed in some samples that showed banding from rolling. Prior to melting, it appears that solid-state metallic bonding occurs during nugget development.
TL;DR: In this paper, the texture evolution induced by tensile deformation and by deep drawing was investigated using the series expansion method and the results indicate that the initial texture changes drastically after a few percent of plastic strain and evolves towards a single orientation for which the direction is aligned with the tensile or drawing axis.
Abstract: The texture evolution induced by tensile deformation and by deep drawing was investigated. For this purpose, the textures of 3 types of steel (rimmed, Al-killed drawing quality, and interstitial free) were measured and analyzed using the series expansion method. The results indicate that the initial texture changes drastically after a few percent of plastic strain and evolves towards a single orientation for which the direction is aligned with the tensile or drawing axis. The distinct earing behaviors of the AKDQ and IF steels (i.e. 4-eared for the Al-killed and 6-eared for the interstitial free) are interpreted in terms of differences in the sharpness and homogeneity of their ND-fibres and in the influence of the {332} and the partial {223} fibre.
TL;DR: In this paper, an electroless Ni-P plating was introduced as the interlayer in the modification of the TiN coating, and the corrosion behavior of the coating assembly was evaluated using the salt spray test and the polarization technique.
Abstract: TiN films were prepared by reactive r.f. magnetron sputtering on low carbon steel substrates. An electroless Ni-P plating was introduced as the interlayer in the modification of the TiN coating. The corrosion behaviour of the TiN coating assembly was evaluated using the salt spray test and the polarization technique. For a thicker Ni-P interlayer (greater than 5 μm), no appreciable corrosion was observed up to hundreds of hours after salt spray testing. The polarization curve indicates a barrier-type passive film in the TiN/Ni 3 P/Fe coating assembly. The corrosion currents for TiN/Fe, Ni 3 P/Fe and TiN/Ni 3 P/Fe are 200, 40–70 and 6–7 μA cm -2 respectively. It appears that the electroless Ni-P interlayer modified TiN coating has better anticorrosion resistance than pure TiN coating on low carbon steel.
TL;DR: In this article, the microstructure of a hot-rolled low-carbon plate steel has been examined using a combination of light microscopy and scanning electron microscopy, and it has been found that in the hotrolled condition, the micro-structure consists of alternate bands of ferrite and pearlite, together with relatively large, irregular pearlite nodules.
Abstract: The microstructure of a hot-rolled low-carbon plate steel has been examined using a combination of light microscopy and scanning electron microscopy. It has been found that in the hot-rolled condition, the microstructure consists of alternate bands of ferrite and pearlite, together with relatively large, irregular pearlite nodules. These large nodules were found to be comprised of pearlite, intragranularly nucleated ferrite (both Widmanstatten and idiomorphic), together with carbide-deficient and/or carbide-free regions. It is argued that the carbide-deficient and carbide-free regions form as a result of the premature initiation of the pearlite reaction, i.e. pearlite forms prior to the body of the austenite grains attaining the eutectoid composition. In order to model the formation of the banded structure, specimens were reaustenitized at 1050 °C for 10 min and furnace cooled. This heat-treatment cycle produced an austenite grain size which was less than the chemical banding wavelength. A model for the decomposition of austenite, under these conditions, is presented.
TL;DR: In this paper, the corrosion behavior of an American Petroleum Institute N-80 grade steel in 3% sodium chloride (NaCl) in distilled water was studied under a carbon dioxide (CO2) partial pressure of 1.03 mPa (150 psig) at 71°C (160°F).
Abstract: Corrosion behavior of an American Petroleum Institute N-80 grade steel in 3% sodium chloride (NaCl) in distilled water was studied under a carbon dioxide (CO2) partial pressure of 1.03 mPa (150 psig) at 71°C (160°F). The pH was maintained constant at 3.4 for some tests but allowed to fluctuate for other tests. A two-phase, flow-loop test facility for studying effects of flow velocity produced two-phase flow conditions of CO2 gas and liquid in stratified, slug, froth, and mist flow patterns. A test cell for the flow loop allowed for corrosion rate measurements by electrochemical and weight-loss methods using removable pipe spools. Iron carbonate (FeCO3) formed only for low-velocity, single-phase flows where pH increased above 5.0. Corrosion rates after scale formation decreased by almost one order of magnitude. No FeCO3 scale formed in tests involving high-velocity, single-phase flows or two-phase flows. Corrosion rates when no scales formed were independent of pH and flow pattern.
TL;DR: In this paper, threshold hydrogen concentration (CthH) and threshold pH (pHth) for hydrogen-induced cracking (HIC) were determined for commercial sour service linepipe steels exposed to H2S-saturated buffer solutions.
Abstract: Threshold hydrogen concentration (CthH) and threshold pH (pHth) for hydrogen-induced cracking (HIC) were determined for commercial sour service linepipe steels exposed to H2S-saturated buffer solutions. Metallographic examination of the steel samples by optical and electron microscopy showed that ultrasonic C-scan is an effective method for detecting HIC and for locating cracks in exposed steel coupons. A banded microstructure was found to be detrimental to the HIC resistance of clean steels. The obtained pHth values can be used to rank the steels with respect to HIC resistance.
TL;DR: In this paper, preliminary results of ongoing crack growth studies being performed on an API X-65 line pipe steel in a low-pH cracking environment were reported, and the objectives were to reproduce low pH crack growth.
Abstract: Preliminary results of ongoing crack growth studies being performed on an API X-65 line pipe steel in a low-pH cracking environment were reported. Objectives were to reproduce low-pH crack...
Patent•
23 Jul 1993
TL;DR: In this article, a process for manufacturing a medium-carbon steel plate having a graphitization of 50% or more with improved formability and weldability is disclosed, the process comprises the steps of: hot rolling a steel with a finishing temperature of 700°-900° C., the alloy composition of the steel consisting essentially of, by weight %: C: 0.20-0.70, Si: more than 0.30, Si and incidental impurities: balance, cooling the resulting hot-rolled steel plate at a cooling rate of 5°-50° C./
Abstract: A process for manufacturing a medium-carbon steel plate having a graphitization of 50% or more with improved formability and weldability is disclosed, the process comprises the steps of: hot rolling a steel with a finishing temperature of 700°-900° C., the alloy composition of the steel consisting essentially of, by weight %: C: 0.20-0.70%, Si: more than 0.20 but not more than 2.00%, Mn: 0.05-0.50%, P: not more than 0.020%, S: not more than 0.010%, sol. Al: 0.01-1.00%, B: 0.0003-0.0050%, N: 0.002-0.010%, B/N: 0.2-0.8, Cu: 0-1.00%, Ni: 0-2.00%, Ca: 0-0.010%, and Fe and incidental impurities: balance, cooling the resulting hot-rolled steel plate at a cooling rate of 5°-50° C./s, coiling the steel plate at a temperature of 400°-650° C., and optionally, cold rolling the hot-rolled steel plate with a reduction in thickness of 20-85%, and annealing the cold-rolled steel plate at a temperature of 600°- Ac 1 for 1 hour or longer.