Showing papers on "Carbon steel published in 1984"

Evaluation of Corrosion Inhibitors in SO2 Scrubber Solutions

Abstract: Twenty-six compounds were screened via electrochemical measurements to detect any corrosion inhibition properties on carbon steel and AISI 304 316 stainless steels in simulated SO2 scrubbe...

Precipitation of Nb(CN) during high strain rate compression testing of a 0.07 Pct Nb-bearing austenite

Abstract: The recrystallization of austenite in plain carbon steel (C-Mn) following high temperature deformation is a rapid process which may take only fractions of a second to complete. ~-1~ It is also well known 1"2 that additions of minute amounts of elements such as niobium to a C-Mn austenite strongly delay the recrystallization of austenite, and are responsible for the development of pancaked austenite during controlled rolling. While this retarding effect of niobium has been recognized for almost 20 years,11'12 there continues to exist some controversy about the nature of the mechanism responsible for the observed retardation. Some authors 13'14'15 suggest that this retardation results from solute drag effects, while others 16-18'2~ propose that it results mainly from precipitation effects. Results of recent work 7'19 indicate that recrystallization is substantially delayed in Nb-bearing austenite decarburized to carbon levels of 0.002 pct. Since precipitation has been prevented by the decarburization treatment, the observed retardation is attributed to solute drag effects alone. However, the question remains as to which mechanism is, in fact, responsible for the observed recrystallization retardation, when precipitation is allowed as a competing process at the normal carbon levels (->0.02 pct C) typical of microalloyed (MA) steels. Retardation of recrystallization of the microalloyed austenite unequivocally attributable to precipitation effects has been extensively reported from results of experiments performed using different techniques. These include direct studies of precipitation using electron microscopy of thin foils and replica specimens, 7'16-18'2~ gross precipitate extraction, 5'~9 and indirect interrupted mechanical testing methods.6 10.13-15,17-19 However, in most of these studies, the lack of rapid quenching prevented reliable metallographic observations from being made during the first few critical seconds after the completion of the deformation. At the same time, it is well known that C-Mn austenite can undergo significant recrystallization in elapsed times of the order of one second s-1~ when deformed under conditions similar to those employed in the precipitation studies in the MA steels. The inability to observe specimens quenched within a fraction of a second has, therefore, restricted our understanding of the role played by precipitation in the early stages of retardation of recrystallization. The purpose of this paper is to demonstrate that when hot deformation is followed by rapid quenching, it is possible to show clearly that well-developed precipitates do form in austenite in less than 0.5 second. The steel investigated has the following chemical composition, in weight percent: 0,08 C, 1.25 Mn, 0.40 Si, 0.005 P, 0.005 S, 0.07 Nb, and 0.025 N. The steel was

Diffusion treated hot-dip aluminum coated steel and method or treating

Abstract: A solid solution iron-aluminum diffusion alloy coated steel strip is formed by hot-dip aluminum coating a cold rolled low alloy low carbon steel strip preferably having all the carbon in the steel combined with titanium by hot-dip aluminum coating the steel strip and subjecting the aluminum coated low alloy steel strip to a controlled diffusion heat treatment in a non-oxidizing atmosphere for a period and at a temperature which avoid significantly increasing the grain size of the steel, and which effects diffusion of the hot-dip aluminum coating onto the steel to establish a critical surface concentration of aluminum in the iron-aluminum diffusion alloy coating of at least about 8 wt. percent and below an aluminum surface concentration which results in crazing and cracking of the diffusion alloy coating when the diffusion alloy coated strip is fabricated at room temperature. A solid solution iron-aluminum diffusion alloy coated titanium containing low carbon steel strip having an aluminum surface concentration between about 8 and about 10 wt. percent does not exhibit objectionable crazing and cracking of the diffusion alloy coating when the coated steel is severely strained during fabrication at room temperature and has good high temperature oxidation resistance when the diffusion alloy coated steel strip is exposed to oxidizing gasses having temperatures between about 816oC (1500oF) and 982oC (1800oF) after being severaly strained at room temperature.

Cylinder for injection molder and extruder

Abstract: PURPOSE:To obtain the titled cylinder suitable for injection molding or extruding ceramic powders, magnetic powders and metal powders, the abrasion resistance and corrosion resistance of which cylinder would not be deteriorated at high temperatures, by mounting a ceramic liner onto an inner surface of a steel cylinder. CONSTITUTION:A liner 1 of a ceramic (e.g. alumina, carbon silicide, silicon nitride, zirconia, etc.) is integrally molded onto the inner circumferential surface of the cylinder main body 2 of carbon steel, chromemolybdenum steel, stainless steel, or the like with the shrink fit rate of the ceramic being 5/1000 to 10/ 1000 thereby obtaining the aimed cylinder. The thickness ratio of the liner 1 to the cylinder main body 2 is preferably 1:2 to 1:30 at the central barrel section of the cylinder.

Diffusion bonds in iron and a low-alloy steel

Abstract: Diffusion bonds made in both the ferrite and austenite iron phases are compared with the predictions of a theoretical model [1, 2]. The initial formation of the bond is shown to be caused chiefly by surface diffusion along interfacial voids. Subsequent void closure occurs by other densifying mechanisms. The model is also used to successfully predict bonding in a low-alloy medium-carbon steel (En8).

Atmospheric Corrosion of Steel in a Humid Tropical Climate—Influence of Pollution, Humidity, Temperature, Solar Radiation and Rainfall

Abstract: Soviet carbon steel CT-3 plates were exposed in five different places in Havana and the city of Havana (rural, industrial-marine and marine stations). Weight loss was evaluated in periods ...

Method of making a pressure vessel with an anti-corrosion coating, and vessel obtained thereby

Abstract: The affected technical field is that of pressure vessels, and the invention relates to a method of making a pressure vessel with an anti-corrosion coating, and a vessel obtained thereby, which are made such as to avoid the danger of disbonding. The solution consists of a method comprising a first step of deposition by welding on the layer of base material of the shroud (1) a layer (2) of low carbon steel, and a second step of deposition by welding on the low carbon steel layer, a layer (3) of anti-corrosion material.

Structure and properties of heavily cold rolled iron and high strength low alloy and low carbon steels

Abstract: The development of microstructure in α iron and steels during cold rolling has been investigated in the strain range e = 0.5–4.5. In the low strain region (e > 1.5), primary and secondary microbands were identified. The substructure development with strain has been explained in terms of a model in which the volume fraction of micro bands increases with increasing strain at the expense of a uniform cell structure matrix. At large strains, no ‘crystallographic’ microbands were detected, and it is suggested that in this region, slip is controlled by more short range events. The effect of initial grain size on strain hardening has been considered by comparing the behaviour of a coarse grained iron, a medium grain size low carbon steel, and an ultrafine grained high strength low alloy steel. The observations suggest that during cold rolling the flow mechanism will change from being substructure controlled (σ = σ0 + kd−1, where d is the subboundary separation) to grain boundary controlled (σ = σ0 + kd−½...

Manufacture of hollow stabilizer using electric welded pipe

Abstract: PURPOSE:To manufacture hollow stabilizers in large quantities by hardening and tempering each straight electric welded pipe of low carbon steel and carrying out forming. CONSTITUTION:Each straight electric welded pipe of low carbon steel contg. 0.1-0.35% carbon is hardened by rapid heating at >=30 deg.C/sec heating rate by direct electrification heating and by water quenching. It is then tempered by heating at >=30 deg.C/sec heating rate in the temp. range of 120-250 deg.C or 375-500 deg.C by direct electrification heating. The heat treated pipe is bent to the desired shape of a stabilizer by cold working, and it is subjected to stress relief annealing.

Examination of surface defects induced during hot rolling of high-alloy steel bar and rod

Abstract: The authors examine three problems associated with the production of high-alloy steel bar and rod by rolling in hand-operated mills. An outline is given of the mechanics of formation of surface defects and, by using a model material for hot steel (Plasticine) as well as three grades of steel, the defects were examined. Although the work was carried out using hand-operated mills, the conclusions drawn are relevant to commercial continuous mills for producing low-alloy and carbon steel rod and bar. The defects examined were cracking, split ends, and decarburization. The main conclusion is that careful selection of pass sequence, taking into account all the manufacturing and product requirements, is essential in order to control the rate of rejection of rod and bar with these defects

Method of manufacturing a hollow stabilizer

Abstract: A hollow stabilizer manufactured from a material obtained by adding a minute amount (0.001-0.01% by weight) of boron to either a carbon steel tubing having a relatively low carbon concentration of 0.20-0.35% for mechanical and structural purposes or to a carbon steel tubing for general structural purposes. The carbon steel tubing thus provided is bent in a prescribed stabilizer form. The bent tubing is water quenched, for example, to a greater hardness than HRC 43. The water-hardened bent tubing is later tempered to a hardness HRC, ranging between 36 and 43, at a temperature of, for example, 300°-380° C. for a proper length of time. The hollow stabilizer obtained by the aforementioned heat-treating steps has a much greater fatigue strength.

Assembly device of ferritic stainless steel tubes on a carbon steel tube-plate, and process of manufacturing this device

Abstract: Assembly device of tubes of low carbon ferritic stainless steel having 17 to 18.5% by weight of chromium on a tube-plate of carbon steel. It includes a first overlay of low carbon austenitic stainless steel having 11.50 to 14% by weight of nickel and 22 to 25% by weight of chromium on the surface of the tube-plate opposite the plurality of tubes, a second overlay on the first of low carbon austenitic stainless steel having 10 to 12% by weight of nickel and 19 to 23% by weight of chromium extending beyond the upper level of the ends of the tubes, and weld beads with or without filling metal around these ends between these ends and the stainless steel of the second overlay.

Process for production of steel bar or steel wire having an improved spheroidal structure of cementite

Abstract: Herein disclosed is a process for producing a steel bar or steel wire having an improved structure of spheroidal cementite. The process is characterized in that a finish rolling is conducted within a temperature range between Ar 1 and Ar 3 or Arcm with a reduction ratio of at least 20%. The cooling rate of the steel before the finish rolling should be controlled in the following manner: When the hardenability of the steel is not higher than that of 0.15% C plain carbon steel, it is preferable to cool the steel at a cooling rate higher than 250° C./sec. When the hardenability of the steel is between those of 0.15% to 0.4% C plain carbon steel, it is preferable to cool the steel at a cooling rate higher than 10° C./sec. When the hardenability of the steel is not lower than that of 0.4% C plain carbon steel, it is preferable to cool the steel at a cooling rate higher than 2° C./sec. The annealing may be conducted on the same production line as the hot working of the steel for a shorter time duration by an isothermal treatment, slow cooling treatment or repeating treatment. The annealing may be conducted also by a usual annealing method.

Kinetics of Precipitation from Quenched Low Carbon Steel

Abstract: This paper describes new rate equations which fit exactly the experimental data of carbon precipitation from supersaturated α iron. The experimental data reported by Abe and Suzuki, electrical resistivity, thermoelectric power, and Vickers hardness, are used. A low carbon steel is quenched from 700°C and aged isothermally in the range from 35 °C to 300°C. Aging curves are separated into two curves corresponding to characteristic precipitates, and superposition of the two curves elucidates the reason why two-stage aging curves often appear. The separation of aging curves clarifies the temperature dependence of each precipitation, and activation energies of 0.57, 1.21, 0.80, and 1.45 eV are obtained for cluster, e carbide formed below 75 °C, e carbide above 100°C, and cementite, respectively.

Periphery welding method of clad steel pipe

Abstract: PURPOSE:To prevent a base metal component in a weld metal and in a clad steel pipe from being diluted, by joining a solid short pipe of the same component compound as a cladding material to the clad steel pipe by means of frictional welding, etc. CONSTITUTION:A solid short pipe 1 having the same component compound as a cladding material 10a is joined by frictional welding 2, and subsequently, groove work is performed for a pipe end part of the solid short pipe 1. Clad steel pipes 10, 10 prepared in said way are butted, and the periphery is welded by a welding material 4 of a co-metal with the short pipe 1. In this way, a carbon steel base metal 10b is not diluted in the weld metal 4, and the component of the solid short pipe 1 is scarcely varied, therefore, the corrosion resistance and other characteristics are not deteriorated.

Cold rolling method of thin steel strip

Abstract: PURPOSE:To roll a thin strip of a carbon steel having an excellent surface characteristic at a high speed without heat scratching by coating the surface of work rolls with a high-hardness high-heat-conductivity material, high-melting non- solid soln. material, etc. and using a rolling mill oil having excellent mill cleaning property. CONSTITUTION:Any among the high-hardness high-melting material having >=900 Hv hardness and >=1,500 deg.C m.p. high-harness high-heat-conductivity material having >=900 hardness and >=0.15Cal/sec. deg.Ccm heat conductivity at 20 deg.C and the high-melting non-solid soln. material or high-melting high-heat conductivity material having >=2,000 deg.C m.p. is used to coat the surface of work rolls for cold rolling of the thin steel strip. The steel strip is cold rolled by using such work rolls and the rolling mill oil consisting essentially of mineral oil and synthetic oil having excellent mill cleaning property. The seizure of the rolling material and the work rolls is prevented by such method. The thin steel strip having high quality is thus produced at a high speed and high yield by high-draft rolling.

Production of thick walled ultra high tension steel

Abstract: PURPOSE:To obtain a thick-walled steel plate having high strength of >=90kg/ mm. with >=40mm. thickness and good and high toughness at a low temp. by setting the content of costly alloy elements such as Cr, Mo, Ni or the like at lower levels by using a high carbon steel and subjecting the steel to hardening and tempering. CONSTITUTION:A steel contg., by weight, 0.20-0.35% C, <1.0% Si, 0.30-1.50% Mn, 0.3-2.5% Cr, 2.0-4.5% Ni, 0.2-1.0% Mo, 0.002-0.1% Al and <=1.5 Mn/Cr is hot rolled. The P in the steel is preferably incorporated at <=0.15% and S at <=0.010%. The steel hot-rolled to a prescribed thickness is subjected to a hardening heat treatment for eigher cooling quickly online the steel from the temp. above Ar3 or cooling once the same by allowing the steel to cool then reheating the steel to the Ac3 point or above and quickly cooling the steel from the Ac3 point or above. The steel subjected to the hardening heat treatment is subjected to a tempering heat treatment in a ferrite region, whereby the intended thick- walled ultra-high tension steel is obtd.

Manufacture of hot-rolled low-carbon steel sheet having superior deep drawability

Abstract: PURPOSE: To obtain a hot-rolled low-C steel sheet having superior deep drawability at a low cost by rolling a low-C Mn steel slab at a specified total draft in a specified rolling time in the final stage and carrying out finish rolling at the Ar 3 point or below and coiling at a regulated temp. CONSTITUTION: A steel slab contg. <0.04wt% C and <0.5wt% Mn as principal components is hot rolled at ≥40% total draft. At this time, rolling in the final stage or the preceding stage is carried out in ≤0.3sec. Finish rolling is finished at the Ar 3 point W the Ar 3 point -50°C, and the resulting steel sheet is quenched and coiled at 550W700°C. By this method, the slab can be taken out at a low temp., and a hot rolled steel sheet having high deep drawability can be manufactured as a substitute for a cold rolled steel sheet without requiring any special element. COPYRIGHT: (C)1986,JPO&Japio

Production of clad steel plate

Abstract: PURPOSE:To obtain a clad steel with good yield without requiring a large scale device by specifying heating temp. and draft according to the quality of a cladding material of a belt-like metal in an atmospheric atmosphere in the stage of joining the cladding material to a base material of a belt-like carbon steel or low alloy steel by lap rolling. CONSTITUTION:A base material 1 and a cladding material 2 which are wound like a coil are passed respectively through heating furnaces 3, 4 and are then superposed on each other. The superposed materials are rolled and joined by rolling rolls 5 to a clad plate which is further rolled to a prescribed thickness by rolling rolls 6. The clad plate is then annealed in an annealing furnace. The material 1 and the material 2 are heated in an atmospheric atmosphere or the atmosphere added with non-oxidative gas to the prescribed temp of 250-600 deg.C according to the quality of the material 2 and are rolled once at the prescribed draft of 15-65%. After the material 1 and the material 2 are thus joined, the joined material is rolled cold or warm and is annealed at the prescribed temp. of >=300 deg.C according to the quality of the material 2. Substantial joint strength is obtd. by annealing alone after joining according to the quality of the material 2.

In situ Characterization of Electrochemically-formed Oxide Films on Low Carbon Steel by Diffuse Reflectance Spectroscopy

Abstract: The mechanism of corrosion of steel and iron is studied by the combination of cyclic voltammetry and diffuse reflectance absorption spectroscopy (DRS). The method is especially valuable to investigate samples with rough or polycrystalline surfaces without prior preparation as it is the case for cold rolled low carbon steel. The sensitivity depends on the absorption coefficients of the oxide film. In the case of the Fe2+/Fe3+-redox-system it is possible to investigate the formation and reduction of the passive layer even with under monolayer coverage. The spectroscopic measurements allow to identify the formation of Fe2+-Fe3+-mixed oxides which are responsible for protective or non-protective films. Spectra of different modifications of iron oxide powders are also given.

High-strength low-carbon steel material having superior heavy workability

Abstract: PURPOSE: To obtain a high-strength low-carbon steel material having superior heavy workability by preparing a steel material contg. specified percentages of C, Si and Mn in Fe and by providing a metallic structure consisting of specified phases. CONSTITUTION: A steel material consisting of, by weight, 0.01W0.30% C, ≤1.5% Si, 0.3W2.5% Mn and the balance Fe with inevitable impurities or further contg. at least one among 0.005W0.20% Nb, 0.005W0.30% V and 0.005W0.30% Ti is prepd. The steel material has a metallic structure contg. acicular martensite, bainite or a mixture of them dispersed uniformly in a ferrite phase by 15W 40vol% basing on the amount of the ferrite phase. The dispersed phase is a phase produced by transformation at a low temp., and it has ≤3μm average grain size. COPYRIGHT: (C)1985,JPO&Japio

Effect of Phosphorus Ion Implantation on Corrosion of Steel

Abstract: Phosphorus ions were implanted in low carbon steel specimens in dosages of up to 2×1017 P ions/cm2 with ion energies of 60 and 190 keV to induce improved corrosion resistance characteristics. Anodic polarization measurements were used to characterize the corrosion behavior in pH 8.5 buffered borate solutions. Results showed that implanted phosphorus stabilized the passive oxide film to the extent that the breakdown potential for localized corrosion in the presence of chloride ions improved dramatically. The degree of stability of the passive film was shown to be related directly to the number of phosphorus ions implanted and their proximity to the surface. Surface film analysis indicated that phosphorus ion implantation promoted a thickening of the oxide film over a wide range of potentials, but that phosphorus did not become a significant part of the film.

Prevention of stress corrosion cracking

Abstract: PURPOSE:To prevent the stress corrosion cracking of a structural metal material, by a method wherein corrosion resistant metal plating is applied to the surface of the sensitized structural metal material contacted with a corrosive environment and welding is subsequently performed. CONSTITUTION:At first, structural metal matrix materials 1, 2 to be welded are subjected to edge preparation processing according to necessity and corrosion resistant metal plating 7 is applied to the surface (inner surface) of the range 5 sensitized by welding of the matrix materials 1, 2. Subsequently, the matrix materials 1, 2 are welded by a welding metal 3. In this case, the structural metal material comprises a stainless steel, a copper alloy, an aluminum alloy or a carbon steel and the corrosion resistant metal to be plated is nickel, chromium, copper, silver, gold or platinum.

Role of MnS inclusions in hydrogen assisted cracking of steel exposed to H2S saturated salt solution

Abstract: The role of MnS inclusions in the crack growth behaviour of quenched and tempered medium carbon steel exposed to H2S saturated salt solution has been studied. In this environment, crack extension in the short transverse orientations occurs in a discontinuous manner which is associated with the development of inclusion nucleated subsidiary cracks ahead of the main crack. The high hydrogen activity of the H2S saturated salt solution causes both matrix embrittlement and the accumulation of hydrogen at the inclusion/matrix interface in a molecular form. In the case of specimens containing pre-existing cracks, the formation of secondary cracks in the short transverse plane ahead of the main crack is caused by pressurization effects at colonies of closely spaced large inclusions. The discontinuous growth observed in these specimens is attributed to the operation of the pressurization mechanism.

Effect of Prestrain Upon Acoustoelastic Properties of Carbon Steel

Abstract: Earlier measurements on steels containing different amounts of carbon show that the stress acoustic c onstants (SAC’s), which measure higherorder elastic material properties, are linearly dependent on the amount of ferrite phase in these steels. In order to further c haracterize the behavior of higher-order elastic properties of carbon steels, the p resent s tudy investigates t he effect of prestrain upon the SAC‘s of 1016, 1045 and 1095 carbon steels. The SAC’s are measured for each of the t hree alloys after varying amounts of prestrain are produced by tensile loading into the plastic range. The SAC measurements are made in the linear elastic range using small tensile as well as compressive loads. Stress-induced changes in ultrasonic v elocity are measured using a pulsed phase lockeg loop interferometer with resolution of parts in 10 . Results of this study show that the SAC‘S measured in tension increase while the SAC’S measured in compression decrease as a result of prestrain. The average of these two quantities, however, remains unchanged as a function of the prestrains used in this investigation. This average is found to change linearly with the amount of ferrite phase present in the al.loys and confirms previous findings.