Showing papers on "Carbon steel published in 1974"

Wear-resistant, nonabrading tic article and process for making

Abstract: A wear-resistant, nonabrasive metal article, such as a thread guide, comprising a plain carbon steel substrate with a thin, dense, continuous coating of titanium nitride, having a thickness of about 1 to 5 microns, chemically vapor deposited at reduced pressure on said steel substrate, and preferably a thin, continuous, smooth, titanium carbide coating, having a thickness of about 5 to 25 microns, chemically vapor deposited at reduced pressure on said nitride coating, the carbide coating having HK 50 hardness of 3600 to 3900 and a surface finish of 0.2 to 0.5 micron.

Electron Microscopy and Diffraction Study of the Carbide Precipitated at the First Stage of Tempering of Martensitic Medium Carbon Steel

Abstract: Crystal structure and precipitation mode of the carbide in a martensitic 0.45 wt%C steel tempered at 120 and 200°C have been studied by means of electron microscopy and selected area diffraction. In both plate-like and lath martensites, the precipitated carbide is η-Fe2C like the previous case of high carbon steel(Acta Met.,20(1972),645). The crystal morphology and the orientation relationships between the carbide and the matrix are also the same. In general, the precipitation occurs along dislocations, but it has been found that grain boundary precipitation also takes place in the non-parallel lath region and that in fine grains in this region the carbide precipitation does not occur. Some discussions are given to the crystal structure and the precipitation mode of the carbide. (Received September 4,1973)

Continuous carburizing method

Abstract: An improved method for continuously carburizing low carbon cold rolled coil stock is disclosed. The carburized product is characterized by the absence of proeutectoid ferrite. The method comprises heating low carbon steel stock in the austenitizing range of 950°-1150°C. (1750°-2100°F.) in a continuous heat treating furnace wherein the furnace contains a high carbon availability so that residence time is of a short duration; homogenizing the stock so as to attain uniform macro distribution of carbon across the length, width and thickness of the stock and quenching the stock so that a uniform micro distribution of carbon is attained.

The effect of cyclic stressing on the oxidation of a low-carbon steel

Abstract: The effect on oxidation of cyclically stressing a low carbon steel was studied at tempera-tures of 500 and 570°C. It was found that if the cyclic strain was above a threshold value which corresponded to the fracture strain of the surface scale, then the oxide growth rate increased both at 500 and at 570°C. The oxide fracture strains under fatigue conditions were found to be in the range 2.7 - 5.1 x 10-4. The mechanism of the process is discussed in relation to oxidation kinetics and the mechanical properties of the growing surface scales.

Aluminum coated steel

Abstract: An aluminum coated low alloy mild steel sheet material and a method of making said material which contains a small amount of titanium sufficient to precipitate all the carbon in the low carbon steel and provide a slight excess of uncombined titanium dissolved in the steel and containing molybdenum in an amount less than 1 percent by weight with the balance being mainly iron and incidental impurities. The aluminum coated material exhibits extraordinarily high creep resistance and rupture strength for a low carbon steel material at a service temperature above 1,250 DEG F (i.e. 1,300 DEG F) in an oxidizing atmosphere.

Pressure bonded, low yield strength composite

Abstract: A pressure bonded composite article and a method for producing it. The article is comprised of a layer of plain carbon steel containing up to 1.5% of carbide former, a layer of stainless steel, and a layer of not readily oxidizable metal therebetween. The method comprises the steps of superimposing the layers, heating them at a temperature of from 1200° to 2400°F, and subsequently hot rolling them.

Hot-rolled low-carbon steel strip with an excellent press-workability capable of forming smooth pressed surface and a method of making the same

Abstract: Hot-rolled low-carbon steel strip with an excellent press-workability capable of forming a smooth pressed surface consisting essentially of up to 0.12 wt. % carbon, up to 0.01 wt. % nitrogen, up to 0.0094 wt. % boron, and other specific optional ingredients, the B(%)/N(%) ratio being 0.3 to 0.94. The micrograin size number, JIS, of ferrite in the steel strip as hot-rolled is 7 to 9. The steel strip is made by hot-rolling while controlling the temperatures at the entry and delivery ends of a hot-strip finishing mill.

Method of coating carbon steel

Abstract: A method of preparing carbon steel strip and sheet for hot dip metallic coating in a Selas-type direct-fired furnace, wherein the atmosphere in the furnace is controlled to contain from about 3% oxygen to about 2% excess combustibles by volume, thereby forming a thin iron oxide film on the carbon steel surfaces. The strip and sheet is then heated in a subsequent furnace containing at least 5% hydrogen by volume at a temperature sufficient to reduce the oxide film, viz., at least about 675° C. The direct-fired furnace is preferably operated at stoichiometrically equivalent fuel:air ratios.

Method of making ball studs

Abstract: A method of making a ball stud in which a low carbon steel or a low carbon alloy steel is used as a starting material, the material is coldly formed into the ball stud, a lower carbon content and smaller carburization depth are selected in comparison with an ordinary carburization method and diffusion heat treatment of said material is carried out at substantially the same temperature as the carburization temperature, then said material is subjected to quenching and tempering treatment and finally induction hardening is applied only to the ball portion of said ball stud.

Effect of Environment on the Fatigue Behavior of a Medium Carbon Steel

Abstract: The effects of environment on the fatigue behavior of a quenched and tempered medium carbon steel have been studied. Alternating tension, low cycle fatigue tests were performed at room temperature in humid and dry hydrogen, hydrogen sulfide, and argon, as well as in ambient air. With respect to behavior in air, humid hydrogen, and to a lesser extent, argon caused an increase in fatigue life, while hydrogen sulfide caused a decrease. These results are explained by consideration of the processes occurring at the tip of a growing fatigue crack where the freshly exposed clean metal surface interacts with the environment. In some cases, such as humid hydrogen, it is believed that the presence of a condensed water film can act as a shield to prevent reactions with hydrogen or oxygen which would otherwise increase crack growth rates. In the presence of hydrogen sulfide or dry hydrogen, however, chemical reactions are believed to occur leading to hydrogen embrittlement. The result is a change in the frac...

Method of providing an intermediate steel layer for chrome plating on rotor housings

Abstract: A method (and resulting product) is disclosed for making rotor housings useful in a rotary internal combustion engine. The housing is preferably sand cast; the internal epitrochoid surface is flame-spray coated with a thin layer of nickel-aluminide, flame-spray coated with a thicker layer of plain carbon steel, and then plated with chromium. The resulting casting-coating composite provides enhanced wearability, increased dimensional stability, and reduced internal stress of the coatings.

Method of producing a composite material

Abstract: A composite material which has a substantially reduced incidence of defects after drawing, and a method of producing it. The composite material is comprised of at least one layer of plain carbon steel containing up to 1.5 percent of carbide former present in a carbide former-to-carbon ratio of from about 1.5 to about 25 and at least one layer of stainless steel. It is formed by pressure bonding carbon steel containing carbide former to stainless steel.

Pressure bonded composite material with low yield strength

Abstract: A composite material which has a substantially reduced incidence of defects after drawing, and a method of producing it. The composite material is comprised of at least one layer of plain carbon steel containing up to 1.5% of carbide former present in a carbide former-to-carbon ratio of from about 1.5 to about 25 and at least one layer of stainless steel. It is formed by pressure bonding carbon steel containing carbide former to stainless steel.

The Effect of Hot-Band Structure on Texture Development in Low-Carbon Steel Sheet

Abstract: Low-carbon rimming steel has been hot rolled from 25 mm-thick slab to 2·5 mm sheet under conditions which simulated, as far as was possible in the laboratory, full-scale practice. After hot rolling, the strip was spray-cooled to a temperature corresponding to the coiling temperature and thereafter slowly cooled. Microstructures and textures were characterized at this stage. A standard cold-rolling and annealing treatment was given before the measurement of R values. Within a certain range of hot-finishing temperatures and spray-cooling temperatures, high R values (∼1·7) were developed. Comparisons were made with a steel of similar composition commercially hot rolled to 2·5 mm and then subjected to the same cold rolling and annealing treatment. The laboratory and commercial hot-rolled steels showed quite different grain-growth characteristics, which could not be attributed to differences in the average grain size or texture at the hotband stage. Subtle microstructural differences at this stage are ...

Nitrided boron steel

Abstract: A method of economically producing steel parts having high case hardness and commensurate core properties, the parts being formed from low carbon steel containing about 0.25 to 0.50 percent of carbon, about 0.80 to 1.60 percent of manganese, about 0.40 maximum percent of silicon, about 0.0003 to 0.005 percent of boron, up to approximately 0.1 percent of a suitable nitriding agent such as vanadium, titanium tungsten, aluminum, zirconium, columbium, chromium or molybdenum, balance essentially iron, the boron and nitriding agent being in an uncombined or atomic form, the parts being hardened to develop desirable core properties and then being nitrided to develop case hardness.

Effect of Manganese and Salfur on Austenite Grain Size and Recrystallized Ferrite Grain Size After Cold Rolling of Low Carbon Steel

Abstract: 鋼のオーステナイ ト結晶粒度は,い わゆ る鋼質 を示す 一つの指標 として利用 されてお り ,従 来細粒鋼 といわれ るものはA1やNbな どの窒 化物,炭 化物生成元素の添 加に よつて得 られている.リ ム ド鋼には これ らの元素は 存在せず,粗 粒鋼に属す るもの と考え られ たが,冷 延鋼 板用の熱 延板 をオーステナイ ト化 してオーステナイ ト結 晶粒を調査 した結果,中 には細粒鋼 と同様 な粒成長挙動 を示す ものが存在 し,細 粒材か ら粗粒材にいたるまで様 々な粒度の ものが見い出された.こ れ らの熱延板 を冷間 圧延 し焼鈍す ると,細 粒材 は焼鈍後 のフラ ェイ ト結晶粒 径が小 さく,粗 粒 材は大 きい傾向が認め られ た. 冷 延鋼板の フェライ ト結晶粒度はその機械的性質に密 接な関係があ り,通 常粒径 の大 きい方が降伏 点は低 く伸 びは大で深絞 り性の指標 r値 も大 きく1),プ レス成形性 はよいとされている.こ の フェライ ト結 晶粒度は組成 と 冷延圧下率,焼 鈍条件などの製造条件 とに大 きく影響 さ れ るが,リ ム ド鋼の場合,成 分元 素 としてはCの ほかに S,Oお よびMnな どが支配的 であるといわれ てお り2) ~5) ,フ ェライ ト結晶粒 度に影響す る成分元素はオース テナイ ト結晶粒度にも影響す ることが予想 された. ところが最近藤田 らはこれ らの元素の オーステナイ ト 結 晶粒度に対する影響 を検討 し6)7),Cは0.5%ま での 範囲で細粒化の効 果が大 きいが,Mnの 効 果は小さく, 0の 影響 は十分に確認 できず,Sは 影響な しと報告 して いる.し か しなが ら冷 延用 リム ド鋼のC量 は0.03~0.06 %程 度,Mnは0.25~0.35%程 度で,こ の範囲の変 化 では,オ ース テナイ ト結晶粒度の大幅な変化は考え られ ない.こ の リム ド鋼 におけ る現象を説明で きない理 由の

Method of producing long-length articles from hot-rolled carbon steel and article produced thereby

Abstract: A method of producing long length articles from hot-rolled carbon steel is disclosed. A distinctive feature of the method, is that the operations of cold and warm plastic deformation of a wire rod alternate in succession at least twice.

High strength ductile hot rolled nitrogenized steel

Abstract: Aging hot rolled nitrogenized low carbon steel is treated to produce a material having a level of ductility during forming and a yield strength after forming which is comparable to the 80,000 psi yield strength hot rolled low alloy (HSLA) steels. The method includes the steps of (1) rapidly heating the steel within the alpha plus gamma region of the appropriate phase diagram for the steel and quenching; (2) tempering for example at about 400°F. for about 2 minutes and cooling; (3) deforming at least 2 percent, and (4) aging to develop the 80,000 psi yield strength.

High Strain Rate Testing of a Low Carbon Steel to High Strains over a Range of Temperatures, Using a Torsional Hopkinson-bar Apparatus

Abstract: : A recent version of a torsional Hopkinson-bar apparatus, capable of high strains such as found in metal working, is briefly described. The magnitude of axial forces and bending waves in the system during a test is determined and their effects on measured flow stress shown to be negligible. Test results for a low carbon free-machining steel are given, for shear strain rates up to 4330/s and temperatures up to 500C. In all but one case this material fractured in the dynamic tests before the potential strain was realized, but shear strains of about 1.3 were usually obtained. Because of the large strains, adiabatic heating during the dynamic tests had a substantial effect on the stress-strain curves. The dynamic strain ageing effect was clearly evident from the tests at 400C and 500C.

Thermodynamic activity of carbon in recarburizing

Abstract: 1. We determined the numerical values of the interaction parameters of Si, Al, Cr, Ti, V, Mo, W, Mn, and Ni, characterizing the effect of alloying elements on the thermodynamic activity of carbon for recarburizing and carburizing in an endothermal atmosphere at 950°. 2. A quantitative relationship (7) was established for the change in the thermodynamic activity of carbon in austenite under the influence of complex alloying, making it possible to calculate the carbon potential for recarburizing and carburizing of alloy steels. 3. The applicability of formula (7) was determined for carburizing of impurity-free alloys of the Fe−Cr−Ni, Fe−Ni−Si, Fe−Cr−Ni−Si, and Fe−W−Mo systems and steels 45, 45G2, 60, 60S2, U10, and ShKh15 after recarburizing. 4. Knowing the activity coefficient of carbon in complex-alloyed austenite, one can determine the necessary carbon potential of the atmosphere for a given alloy steel, using the gas-metal equilibrium diagrams for carbon steels.