Showing papers on "Carbon steel published in 1989"

Time‐Resolved Impedance Spectroscopy of Mild Steel in Concentrated Hydrochloric Acid

Abstract: Inhibitor adsorption is specific and leads to decreased surface heterogeneity; this is demonstrated in tests with the acetylenic alcohol 1-octyn-3-ol. Finally, corrosion of steel in 28% HCl (8.7N) is fundamentally different than in 15% HCl, and the inhibition mechanisms in the two media differ as well

Effect of phosphorus on the formation of retained austenite and mechanical properties in Si-containing low-carbon steel sheet

Abstract: The effect of phosphorus and silicon on the formation of retained austenite has been investigated in a low-carbon steel cold rolled, intercritically annealed, and isothermally held in a temperature range of bainitic transformation followed by air cooling. The steel sheet containing phosphorus after final heat-treatment consisted of ferrite, retained austenite, and bainite or martensite. Phosphorus, especially in the presence of silicon, in steel was useful to assist the formation of retained austenite. Mechanical properties, such as tensile strength, uniform elongation, and the combination of tensile strength/ductility, were improved when phosphorus was increased up to 0.07 pct in 0.5 pct Si steel. This could be attributed to the strain-induced transformation of retained austenite during tensile deformation. Furthermore, two types of retained austenite were observed in P-containing steel. One is larger than about 1 μm in size and usually exists adjacent to bainite; the other one is of submicron size and usually exists in a ferrite matrix. High phosphorus content promotes the formation of stable (small size) austenites which are considered to be stabilized mainly by their small size effect and have a different formation mechanism from the coarser retained austenite in the lower P steels. The retained austenites of submicron size showed mechanical stability even after 10 pct deformation, suggesting that these small austenites have little effect on ductility. The 0.07 pct P-0.5 pct Si-1.5 pct Mn-0.12 pct C steel showed a high strength of 730 MPa and a total elongation of 36 pct.

Pitting Corrosion of Carbon Steel in CO2-Containing NaCl Brine

Abstract: Studies of the susceptibility of carbon steel (line pipe steel) to pitting were performed at room temperature in deaerated, NaCl-saturated CO2-containing solution simulating natural brine....

The relationship between the strain-hardening exponent n and the microstructure of metals

Abstract: To investigate the relationship between the strain-hardening exponent n and the microstructure of metals, two kinds of metal are chosen: pure aluminium specimens of different grain sizes, and plain carbon steel specimens with different sizes and amounts of spheroidized cementite. The results show that in the plain carbon steels the n value depends only on the interparticle spacing of cementite, which is related to the two parameters, the volume fraction f and the particle size d. If the interparticle spacing of cementite is considered as the mean free path (MFP) of dislocation motion, the n value of metals is proportional to the MFP. It is the MFP that controls the strain-hardening behaviour of materials.

Corrosion of carbon steel in an aqueous carbon dioxide environment. I: Solution effects

Abstract: Essais de corrosion de deux aciers au carbone dans l'eau distillee additionnee de CO 2 super-pur. Mesure des vitesses de corrosion en fonction de la pression partielle de CO 2 , du pH et de la vitesse d'ecoulement. Analyse des produits de corrosion formes

Influence of Tin Coating on Wear of High Speed Steel Tools as Studied by New Laboratory Wear Test

Abstract: A new laboratory wear test for simulating cutting tool wear is proposed in which the contact conditions in machining are reproduced by letting a tool material pin slide continuously against a fresh countermaterial surface. Wear tests with high speed steel (HSS) pins in the uncoated and TiN coated conditions have been performed. A wear mechanism analysis demonstrates that the simulated tool wear test is able to reproduce closely the major wear mechanisms operating when machining with HSS tools. The advantage of laboratory testing over machining is that the continuous tool wear processes can be studied without the overlapping effects from edge deterioration by plastic deformation and chipping. The new test setup has been used to study the effects of TiN coating on the wear processes on HSS cutting tools. The TiN coating was found to enhance tool wear resistance greatly when sliding against plain carbon steel or quenched and tempered steel. This is due to the superior resistance to both abrasive and ...

Corrosion of carbon steel in an aqueous carbon dioxide environment

Abstract: A water phase during the travel in long gas transport pipes will accumulate increasing amounts of Fe/sup 2+/ corrosion product For a pipeline with an unprocessed well stream of gas, liquid hydrocarbon, and condensed water, the Fe/sup 2+/ buildup in the water phase can have a major influence on the corrosion of carbon steel The most important effect is that sufficiently high amounts of Fe/sup 2+/ lead to the formation of protecting corrosion films These experiments were conducted to achieve better insight into the corrosion phenomena occurring in the water phase of a gas pipeline with liquid drop out and no formation water, ie, with Fe/sup 2+/ and CO/sub 2/ as the main constituents in the water Most research regarding oil- and gas-related CO/sub 2/ corrosion of carbon steels treats uniform corrosion in absence of FeCO/sub 3/ films When corrosion rates are predicted from these experiments, rate forecasts tend to become too high because the protection offered by corrosion films is neglected To improve the situation, the first aspect is to clarify under which conditions films form and then to understand their protecting properties

Environmentally assisted stress-corrosion cracking of high-strength carbon steel patented wire

Abstract: High-strength carbon steel patented wire is widely used in the skeleton of buildings and bridges, cemented in concrete in order to counterbalance severe compressive stresses being developed in the reinforced structures. For a number of reasons which are beyond the scope of this study, a reinforced wall of such a structure was severely cracked and the skeletal high-strength carbon steel wires were exposed to environmental corrosive conditions. Soon thereafter, a number of wires failed while being subjected to a tension stress lower than their strength

Void formation, void growth and tensile fracture of plain carbon steel and a dual-phase steel

Abstract: Void nucleation and void growth studies in a 1018 normalized steel and a dual-phase steel were undertaken to determine whether longest voids, determined by serial sectioning, grew linearly with strain or whether growth of these voids accelerated continuously. For both materials longest-void growth accelerated continuously with strain. This behavior was attributed to an aligned microstructure which favored local multiple-void nucleation, growth and coalescence. The spacing between these localized voids was much smaller than the average spacing between voids.

Influence of nitrogen ion implantation on hydrogen permeation in an extra mild steel

Abstract: This paper presents the first results on the effect of nitrogen implantation on hydrogen permeation in steels. Nitrogen can modify superficially the steel's chemistry and/or microstructure depending on the fluence and thereby affect the processes of hydrogen diffusion and trapping. The implantations were performed on low carbon steel specimens with different nominal doses (1% to 10% and 33% nitrogen in a superficial layer of approximately 100 to 120 nm). The corresponding microstructures were characterized and permeation tests were conducted at room temperature in a double electrolytic cell. The nitrogen implanted layers on iron affects the electrochemical behaviour of the surface and the permeation in the material. This effect depends on the nitrogen concentration in the layer and on the corresponding microstructure. A continuous Fe2N layer acts as an efficient barrier to hydrogen entry and permeation when the layer is located on the entry face of the permeation membrane. This effect is stronger when the implanted layer is on the downstream face of the membrane. The low permeability values are mainly attributed to a lower hydrogen solubility in the implanted layer, whereas hydrogen trapping on defects and nitride precipitates delay hydrogen penetration.

Bearing race member and method of fabrication

Abstract: A bearing race member composed of steel containing 0.60 to 0.85% carbon by weight, 0.5 to 1.0% by weight in a single content or total contents of Si and Al, and 13 ppm or less oxygen, wherein said bearing race member is quenched and subsequently tempered to contain 15% or less retained austenite therein. Even though basically made of structural carbon steel, the bearing race member has a long life equal to that of high-carbon chromium bearing steel and is superior in dimensional stability and crack fatigue strength.

Factors Limiting the Cathodic Current on Painted Steel

Abstract: The cathodic properties of painted steel specimens exposed to air-saturated artificial sea water have been examined. The painted steel was cathodically polarized by galvanic coupling to freely exposed steel. Both the magnitude of the cathodic current and the change with time were found to depend on the paint used. The cathodic current is most probably limited entirely by the paint film resistance. Themagnitude of the resistivity was found to vary from 10 9 Ω-cm to 10 13 Ω-cm

Formation of magnetic grating on steel plates by electron/laser beam irradiation

Abstract: The steels examined were a ferromagnetic carbon steel, S35C (equivalent to AISI 1035), and a nonmagnetic austenitic stainless steel, SUS 304 (equivalent to AISI 304). The gratings formed were magnetized in a 5.4-kOe field and the profile of the vertical component of magnetic flux leakage from each magnetized grating was measured. Changes of microstructure and mechanical strength of the beam-irradiated portions of the steel plates were also investigated. The measurements of the leakage flux profiles revealed the existence of remanent magnetism in the gratings. Metallographic and mechanical-hardness examinations showed that the original mixed ferrite/pearlite phase in the S35C steel was changed to martensite by beam irradiation. This increased its mechanical hardness. It was also determined that small grains of the ferrimagnetic ferrite phase were precipitated in the base of the nonmagnetic austenitic phase in the SUS 304. >

Formation of hot-top segregation in steel ingot and effect of steel compositions

Abstract: Convection and composition variations in the liquid zone during solidification of H2O-NH4C1 solution, which has the same model of convection as that of steel ingot, are studied. It is shown that a weak convection region forms near the ingot top in the liquid zone at a certain stage of solidification and then develops downward gradually, and the negative segregation is detected in the weak convection region. This interesting phenomenon reveals the formation process of hot-top segregation in steel ingots. The parameterdp L /df L , an important factor affecting the formation of hot-top segregation, is established as a function of the steel composition. When dpL/dfL is decreased by changing the steel composition, hot-top segregation will be impeded.

Formation of silicon diffusion coatings on ferrous alloys from their reaction with silane

Abstract: A method for surface modification of metals using silane-hydrogen reactive atmospheres was developed which results in the formation of a silicon diffusion coating. The silicon is mainly confined in the near surface of the metal and imparts high-temperature oxidation protection. The silicon coatings were characterized with a wide range of analytical techniques including Auger electron spectroscopy. Kinetics of the surface reaction between silane and the metal substrate, as well as the behavior of the coating in oxidizing environments at high temperatures, were studied by a gravimetric technique. Characterization of these silicon coatings on iron, low carbon steel and stainless steel, as well as their applications for high-temperature oxidation, are discussed.

Diffusion bonding of grey cast iron to ARMCO iron and a carbon steel

Abstract: The microstructure transformations produced during the diffusion bonding of grey cast iron to pure iron (ARMCO iron) and to a hypoeutectic steel (0.55% C) have been studied. The indirect determination of the carbon concentration profiles has produced a diffusion equation that relates the microstructure of the bond interface to the bonding temperature and time. A new tensile test specimen is described; this specimen has a variable circular section which allows the determination of true tensile strength of dissimilar diffusion bonds. Metallographic and fractographic studies have shown that the optimum bonding conditions for both types of joint are a bonding temperature at 980° C, for 5 min at a bonding pressure of 4.5 MPa.

Dissolution and reprecipitation of carbonitride precipitates in a low carbon steel by Ar irradiation

Abstract: The effects of Ar bombrdment on carbonitrides produced by N implantation in a low carbon steel are studied by Conversion Electron Mossbauer Spectroscopy. The results show two main features: dissolution and reprecipitation of the produced carbonitrides and modification of the thermal behaviour of the precipitates. Recently we have performed similar experiments bombarding samples of the same steel with He. The comparison of both experiments shows that the Ar post-bombardment is not only more effective in the dissolution and reprecipitation process, but also is more efficient in the carbonitride retention at 450°C.

Method for protecting carbon steel from corrosion in heavy brines

Abstract: A method is described for the inhibition of corrosion of carbon steels due to heavy brine corrosive attack, which employs As +z -containing composition Corrosion inhibiting compositions comprising As +z , alone or in admixture with urea as a synergistic inhibitor, are also described

Process and apparatus for heat-treating carbon steel wires to obtain a fine pearlitic structure

Abstract: Carbon steel wire, which has been maintained at a temperature above the Ac3ransformation temperature, is heat-treated to obtain a fine pearlitic structure by passing it through a tube containing a gas practically without forced ventilation and surrounded by a heat-exchange fluid. Certain relationships between the diameter of the wire, the diameter of the tube and the conductivity of the gas are to be satisfied to ensure cooling of the wire to a temperature below the Acl transformation temperature in a time prior to the time of the pearlitic nose and to effect pearlitization to completion under a nearly isothermal state.

Surface treatment of carbon steel

Abstract: PURPOSE:To simply and easily impart corrosion resistance and weathering resistance on the surface of carbon steel by sticking a metallic layer to be oxidized which consists of phosphorus, chromium and copper, etc., on the surface of carbon steel and furthermore allowing the layer to be applied and formed with a porous primer layer. CONSTITUTION:The surface of carbon steel 1 is stuck with a metallic layer 2 to be oxidized which consists of phosphorus, chromium and copper, etc. Phosphorus is obtained by phosphoric acid treatment and chromium is obtained by chromic acid treatment and copper can be stuck with copper powder as it is. Then this metallic layer 2 to be oxidized is applied and formed with a porous primer layer 3. This primer layer 3 is obtained by applying synthetic resin-base paint such as epoxy-base paint at about 30-40mum thickness by air spray application. The above-mentioned primer layer 3 is made porous with the elapse of time and a protective film 5 is formed by producing oxyoxide 1a and metallic oxide 2a on carbon steel 1 and the metallic layer 2 which are brought into contact with the atmosphere via produced passages 4 and thereby corrosion resistance is imparted on the surface of carbon steel 1.

Laser surface melting of low and medium carbon steels: influence on mechanical and electrochemical properties

Abstract: The influence of a laser melting on both mechanical and electrochemical properties was studied in two carbon steels Geometry and microstructure of the melt zone were first observed by optical and scanning electron microscopy, in various experimental conditions: with different interaction times and power density, for simple and multiple track melting A large hardening was induced by the severe quenching resulting from rapid solidification; therefore the presence of hard points on the surface of the material may increase lifetime of specimens and improve tribological properties This hardening created by the laser melting did not produce deleterious modifications of surface roughness or corrosion behaviour, at least in mildly corrosive saline solutions

Production of alloying hot dip galvanized steel sheet

Abstract: PURPOSE: To produce an alloying hot dip galvanized steel sheet excellent in surface characteristics and coating suitability by plating the surface of a dead- soft carbon steel sheet with trace amounts of Ni and subjecting the above steel sheet to hot dip galvanizing and then to alloying treatment. CONSTITUTION: After the surface of a dead-soft carbon steel sheet containing <0.005wt.% C is plated with trace amounts of Ni by 20-70mg/m 2 , the steel sheet is immersed into a hot dip galvanizing bath to undergo hot dip galvanizing and subjected to alloying treatment to form a Zn-Fe alloyed plating layer, or, the steel sheet is subjected to Ni-Fe alloy plating, in which Ni content and coating weight are regulated, respectively, to 50-200mg/m 2 and 70-1000mg/m 2 , and further to hot dip galvanizing and is then alloyed by means of heating to form a Zn-Fe alloyed plating layer. By this method, the steel sheet suitable for use in automobile sheath and excellent in plane smoothness and coating suitability can be obtained. COPYRIGHT: (C)1991,JPO&Japio