Showing papers on "Carbon steel published in 1995"

Aluminium oxide coated tool

Abstract: There is provided a tool at least partly coated with at least two refractory layers of which one of the said layers is a fine-grained α-Al 2 O 3 -layer which is the top layer along the cutting edge-line and the other a TiC x N y O z - or a ZrC x N y -layer being the top layer on the clearance face. The coated tool exhibits excellent flank and crater wear and high resistance to flaking, particularly when used for machining of low carbon steel and stainless steel. Used cutting edges can easily be identified by the naked eye.

The high speed sliding wear behaviour of boronized medium carbon steel

Abstract: Steels provided with boronized diffusion coatings are known to exhibit excellent wear resistance at low sliding speeds However, the sliding wear behaviour of boronized coatings at high sliding speed is not known In the present study, the high speed sliding wear and friction behaviour of a boronized medium carbon steel has been characterized using a friction dynamometer The boronized samples were tested against a hardened tool steel disc The sliding tests were carried out at velocities up to 8 m s −1 and normal loads up to 2 MPa These tests indicated that the wear rate of the steel can be reduced by about an order of magnitude as a result of boronizing The coefficient of friction of the boronized steel was higher than that of the unboronized steels especially at higher sliding speeds

Corrosion of Carbon Steel in Carbon Dioxide-Saturated Solutions Containing Small Amounts of Hydrogen Sulfide

Abstract: Carbon steel specimens were exposed in carbon dioxide (CO2)-containing brine with different amounts of hydrogen sulfide (H2S) at 70°C and 80°C. The addition of 0.02 mmol/L sulfide, corresp...

Corrosion of mild steel in water

Abstract: An apparatus is described for determining the corrosion behaviour of rotating ( ≤ 2 Hz) metal specimens in test solutions having a range of dissolved oxygen concentrations. Long term tests (up to 150 days) have been carried out on steel specimens at temperatures between 5 and 90°C in triply distilled water, solutions containing 35 ppm Cl-, Teddington tap water, and sea water. Oxygen concentrations ranged from near deaerated (∼ 0·08 ppm O2) to oxygen saturated. Increased chloride and oxygen content increased the mass loss of the specimens during the test period, although a high concentration of oxygen in the absence of chloride ions passivated the surface of the steel. Hardness salts decreased the mass loss of the specimens.

Stress Corrosion Cracking of X-60 Line Pipe Steel in a Carbonate-Bicarbonate Solution

Abstract: An experimental system was developed to reproduce stress corrosion cracking (SCC) of API X-60 line pipe steels in highly alkaline (pH =10) carbonate-bicarbonate (1 N sodium carbonate [Na2C...

Effect of pH on Corrosion Inhibition of Steel by Polyaspartic Acid

Abstract: Polyaspartic acid, a polymeric form of aspartic acid (C4H7NO4), was examined as a corrosion inhibitor for steel as a function of pH, temperature, and hydrodynamic conditions. The temperatu...

A mathematical model for the phase transitions in eutectoid carbon steel

Abstract: A mathematical model for the austenite-pearlite-martensite phase change in eutectoid carbon steel is presented. The model is based on Scheil's additivity rule and the Koistinen-Marburger formula. Existence and uniqueness results are established. To confirm the validity of the model, the Jominy end quench test has been simulated numerically for the carbon steels C 1080 and C 100 W1. The results are in good agreement with measurements

Carbon steel corrosion inhibitors

Abstract: The prevention of corrosion on the surfaces of metallic pipes, heat exchangers, and the like which are in contact with industrial cooling waters, and particularly industrial cooling waters containing low levels of hardness is controlled utilizing a corrosion inhibiting amount of a composition including an alkali metal silicate, a hydroxycarboxylic acid or its water soluble salts, an organophosphonate, and a water soluble polymer which acts as a dispersant. Superior corrosion inhibition is achieved using the compositions of this invention as corrosion inhibitors, particularly in cooling water systems employing mild steel metallurgy.

Photo-Effects of Sol-Gel Derived TiO2 Coating on Carbon Steel in Alkaline Solution

Abstract: On the corrosion protection of carbon steel by sol-gel derived TiO2 coating under the illumination of light, the photoelectrochemical behavior of TiO2/steel system is investigated. The diffusion of Fe ions into TiO2 in the heat treatment of the coating process greatly degrades the photo-effect of TiO2 coating. An Fe oxide layer at the TiO2-steel interface, formed by oxidizing the steel above 500{degree}C in air before coating, has been shown to retard the diffusion. The importance of {alpha}-Fe2O3 in the photo-response of TiO2/steel and the effect of its changing properties with oxidation temperature are discussed. The results on the effect of heat treatment condition in the coating process show that the TiO2/steel specimens exhibit remarkably less noble photopotentials when the heating temperature is increased above 300{degree}C, which is related to the crystallization of TiO2 above this temperature. The ennoblement of photopotential caused by the further increase in heating temperature above 500{degree}C is a result of Fe diffusion through the oxide layer at the interface. Under the optimum conditions for steel oxidation and TiO2 coating, the feasibility of localized corrosion prevention by TiO2 coating under illumination is clearly demonstrated by the fact that the photopotentials of TiO2/steel in deaerated solution are much less noble than the repassivation potential of carbon steel. 22 refs., 13 figs.

Hydrogen Embrittlement Interactions in Cold-Worked Steel

Abstract: Effects of cold work on hydrogen (H) transport, H concentration, and H embrittlement (HE) in type 1020 steel (UNS G10200) exposed in a sour environment were examined. Cold work decreased H...

Characteristics of phase constitution in the Fe-Al alloy layer of calorized steel pipe

Abstract: Microhardness, aluminium content and phase constitution characteristics in the Fe-Al alloy layer of calorized steel pipe were investigated by optical microscopy, microhardness measurements, SEM, electron probe microanalysis, TEM and X-ray diffractometry, etc. Experimental results indicate that the Fe-Al alloy layer of calorized steel pipe was mainly composed of FeAl phase (2.0%–36% Al), Fe3Al phase (13.9%–20% Al) and α-Fe (Al) solid solution, and the microhardness in the Fe-Al alloy layer was 600-310 HM from the surface layer to the inside. There were no higher aluminium content phases, such as brittle FeAl2, Fe2Al5 and FeAl3. The ability to resist deformation and the weldability of the calorized steel pipe were remarkably improved.

FeCrNiMoC alloys produced by laser surface alloying

Abstract: Several FeCrNiMoC alloys were produced by laser alloying on plain carbon steel substrates, using the blown powder technique. It was found that a careful selection of the laser treatment parameters results in alloyed layers free of defects and with a homogeneous chemical composition. The structures were martensitic, fully austenitic and austenitic-ferritic, depending on the chemical composition. The high cooling rates were found to affect the austenitic-ferritic structures, which showed a larger quantity of δ ferrite than that predicted by the Shaeffler diagram. Surface alloys produced by laser processing, with chemical composition similar to that of conventional austenitic stainless steels, showed better pitting corrosion resistance than their bulk counterparts produced by conventional techniques, despite their higher carbon content.

Compound layer growth and compound layer porosity of austenite plasma nitrocarburised non-alloyed steel

Abstract: Compound layer growth and compound layer porosity of an austenite plasma nitrocarburised slowly cooled AISI 1020 steel sample were studied by controlling the plasma nitrocarburising atmosphere with nitrogen, hydrogen and methane content in the following proportions: 25 vol.% N2, 73.25 vol.% H2, 1.75 vol.% CH4 at 600 °C. During the iniial stage of plasma nitrocarburising, highly porous surface structures are formed similar to those described as “the open structure of a piece of coral” observed in salt bath nitrocarburising. For a 9 min treated sample a triple layer composed of cementile, compound layer and nitrogen austenite is formed, which further develops into e iron nitride containing a compound layer and the dissociated nitrogen austenite sublayer. Porosity is mainly nucleated and grows at the grain boundaries, the carbon-enriched region and places where α-iron forms. The structures of quenched and annealed samples were also examined. Pure e compound top layer can be retained after quenching. This layer is unstable at this gas composition and transforms to γ′, α-iron (and Fe3C) containing e during slow cooling. Annealing enhances the core property of the plain carbon steel by transforming the martensite and residual nitrogen austenite into bainite.

Effect of cooling rate after hot rolling and of multistage strain aging on the drawability of low-carbon-steel wire rod

Abstract: Tensile testing was used to simulate the multistage strain aging occurring in low-C steel during the relatively short intervals between dies in a multiple-die wire-drawing machine. The effects were examined of three simulated post-hot-rolling cooling rates and three thermal treatments on the strain-aging susceptibility of a high- and a low-N steel. This was measured by applying a 6 pct tensile strain, followed by aging at either 65° or 100 °C for 20 seconds, and then pulling the specimen to failure at room temperature. Increases in flow stress and decreases in the elongation to fracture both indicated high susceptibility to strain aging. It was found that the nitrogen content, the cooling rate from the hot-rolling temperature to about 300 °C, as well as the cooling rate below 300 °C, all have dramatic effects on the strain-aging behavior. Moreover, multistage strain aging is more severe than single-stage strain aging. The implications of these observations on increasing the drawability of low-carbon-steel wire are discussed.

Error induced by local yielding around hole in hole drilling method for measuring residual-stress of materials

Abstract: The hole drilling strain gauge method described in ASTM standard E837 is a popular methodfor measuring residual stresses near the surface of a material. However, some measuring errors have been found that may affect the accuracy of the measurement. The present paper aims to improve the accuracy by analysing the errors caused by local yielding around the hole. The materials used were 304 stainless steel, 5052 H32 aluminium alloy, and 1018 low carbon steel. The experimental results showed that the error induced by local yielding around the hole is negligible when the residual stresses measured are less than 65% of the yield stress. The maximum errors are in the range 32–47% and occur when the calibrated tensile stress is 95% of the yield stress of the test material. The maximum plastic error occurs in the perfect elastic–plastic material. The plastic error increases as the value of the Young's modulus of the material used increases.MST/3023

Aluminium diffusion coatings on medium carbon steel

Abstract: In the present study, medium carbon steel has been hot dip aluminized (HDA) typically at 973 K/1-2 m, as well as calorized (GAL) by a cementation process, typically 1173-1223 K/2-4 h in a controlled atmosphere. It is found that in HDA. coatings, the outermost pure Al layer is followed by predominantly hard intermetallic phases such as FeAl3 and Fe2Al5, the latter forming a serrated interface with the base. In CAL coatings, depending upon the process parameters (such as pack composition, temperature and time of calorizing), phases such as FeAl and Fe3Al form predominantly and the other Al-rich phases are presented to a lesser extent. Since the HDA presents a quasi-equilibrium situation with regard to phases formed between the base metal and the Al-coating (in view of the very short time of treatment), an attempt has been made to study the phase changes accompanying subsequent isothermal holding (773-933 K/10 m). This leads to the formation of stable equilibrium phases, possibly Fe3Al and solid solution next to the base, resulting in improved endurance to thermal shock (1123 K/WQ) and bending. In the CAL process, parameters have been optimised to produce a mixture of favourable phases, as defined by Pilling-Bedworth parameter

Influence of Heating Temperature and Strain on Surface Crack in Carbon Steel Induced by Residual Copper

Abstract: Synopsis : Mechanism of surface crack formation of steel induced by residual copper (Cu) is investigated using a new technique of Greeble test. Two kinds of experiments were carried out, to clarify the effect of temperature and to understand the behavior of crack growth. Crack is caused by liquid Cu, which precipitates at steel-scale interface during oxidation. However, no crack formed at higher temperature. Micro analysis indicates that it is due to the formation of liquid scale above eutectic temperature of FeO-2FeO¥SiO2. Liquid Cu-precipitates are trapped in the liquid scale area, and they cannot penetrate into austenite grain boundaries. The fact that silicon addition reduces the crack formation also supports this mechanism. Deformation test with various strains reveals that there exist two stages in the behavior of crack growth. At the first stage, crack grows deeper, because liquid Cu penetrates into the boundary. The crack stops growing along the depth direction and opens its width in the second stage, because of the lack of liquid Cu. That means the amount of Cuprecipitates decides the crack depth.

Adsorption of Octadecyldimethylbenzylammonium Chloride to Two Carbon Steel Microstructures as Observed with Surface-Enhanced Raman Spectroscopy

Abstract: Adsorption of the inhibitor octadecyldimethylbenzylammonium chloride (ODBAC) to two carbon steel microstructures, one ferritic-pearlitic and one martensitic, in 0.15 M sodium carbonate (Na2CO3) + 0.15 M sodium bicarbonate (NaHCO3) solution of pH 10 was investigated using surface-enhanced Raman spectroscopy (SERS). ODBAC physisorbed strongly to the ferritic-pearlitic steel and weakly to the martensitic steel. A weak metal-ODBAC bond formed between the metal surface and the ODBAC ring substituent, oriented at an inclined angle to the metal surface. Physisorption of ODBAC was found to depend upon potential, and this was correlated to the potential-dependent presence of magnetite (Fe3O4).

Hadfield steel coatings on low carbon steel by laser cladding

Abstract: Austenitic manganese steels with 12% Mn and 1.2% C, known as Hadfield steels, are of great interest owing to their good mechanical properties, especially their high strengthening ratio during plastic deformation. For many applications only a limited thickness of the surface layer is submitted to wear and therefore manufacturing of coatings with the appropriate FeMnC composition appears an attractive solution. The present work deals with the production, by laser cladding, of Hadfield coatings on a low carbon steel. Sound austenitic layers are achieved with a thickness in the range 0.5 – 1 mm. During cold working, a large Vickers hardness increase is observed (from about 200 to 650 HV). Formation of a texture is accompanied by a γ → α transformation of the fine and dendritic microstructure of the Hadfield coating.

Influence of C16 Quaternary Amine on Surface Films and Polarization Resistance of Mild Steel in Carbon Dioxide-Saturated 5% Sodium Chloride

Abstract: Experiments were performed to understand the behavior of a C16 quaternary amine on initially clean and precorroded surfaces in carbon dioxide (CO2)-saturated brine solutions. Although the ...

Patterns of serrated flow in a low-carbon steel

Abstract: A low-carbon steel was tested in tension. Varying the strain rates and the test temperatures within certain limits produced serrated stress-strain curves. A new finding is that the serrations exhibit all the same regular patterns as are encountered in tests with substitutional alloys.

Cold sterilant solution

Abstract: A sterilant-disinfectant solution which may be used in the cleaning of metallic objects, particularly medical instruments. Medical instruments, which may include brass, copper, aluminium, stainless steel, carbon steel or plastic parts are sterilized or disinfected in an anti-microbial solution. The solution includes a triazole or other component for inhibiting the corrosion of copper and brass. Phosphates or other buffering agents adjust the solution pH in order to prevent the corrosion of steel. Molybdates or analogous compounds may be used to buffer the pH and have been found to inhibit the corrosion of aluminium by oxidizing agents. A sequestering agent is preferably provided for inhibiting hard water precipitation.