Daido Tokushuko Kabushiki Kaisha

Nissan Motor Company Limited

Koyo Seiko Company, Ltd.

Daido Steel Co., Ltd.

Ntn Corporation

Honda Giken Kogyo K.k.

Daido Tokushuko K.k.

Sadayuki Nakamura

Atsuyoshi Kimura

Shozo Abeyama

Yutaka Kurebayashi

Kiyohito Ishida

Makoto Saito

Tetsuo Kato

Yoshio Okada

Tatsuo Fujiwara

Tsuyoshi Nakamura

Takashi Matsumoto

Kikuo Maeda

Jun Yoshida

Masao Goto

Toshikazu Nanbu

Nobuo Kino

Katsuhiko Kizawa

Noriko Uchiyama

Toshihiko Matsubara

Keizo Otani

Toshimitsu Kimura

Tomonori Miyazawa

Atsuhiko Ohta

Makoto Yoshida

Koichiro Inoue

Kenji Isokawa

Takurou Yamaguchi

Hideaki Ohtaka

Hidetoshi Satou

Wataru Naitou

Shigenobu Sekiya

Hiromasa Tanaka

Tosiya Kinami

Kiyoyuki Hattori

Yasushi Matsumura

Yasunori Sato

Kouji Itakura

Toshimitsu Fujii

Noriyuki Shiwaku

Atsumi Hatano

Disclosed is a non-heat treated steel for hot forging, particularly suitable for producing connecting rods of automobile engines. The steel consists essentially of: by weight, C: 0.3-0.8%, Si: 0.1-2.0%, Mn: 0.3-1.5%, P: 0.01-0.15%, Cr: 0-1.0%, V: 0-0.4%, Al: 0-0.05%, N: 0.005-0.03% and the balance being Fe and inevitable impurities, provided that the contents of C, Mn and Cr fulfill the following condition: 1.40[C %]+0.28[Mn %]+0.50[Cr %]&#x2267;0.75 Pearlite area fraction in this steel after hot forging is 50% or more. Notches are provided with laser beam on an intermediate part at the location from which fracture starts, and load is applied. Then, the intermediate is split to be two components (big end or cap and small end/rod for connecting rod). The components are adhered to form the parts.

Non-heat treated steel for hot forging with easy fracture splitting

A heat resistant carburized rolling bearing component is formed of a steel material at least containing, as alloy elements in a matrix, by mass %, at least 0.1% and at most 0.4% of C, at least 0.3% and at most 3.0% of Si, at least 0.2% and at most 2.0% of Mn, at most 0.03% of P, at most 0.03% of S, at least 0.3% and less tan 2.5% of Cr, at least 0.1% and less than 2.0% of Ni, at most 0.050% of Al, at most 0.003% of Ti, at most 0.0015% of O and at most 0.025% of N, and a remaining part of Fe and an unavoidable impurity, and the bearing component is prepared by performing carburizing carbo-nitriding process followed by quenching, and after quenching, tempering at a tempering temperature of at least 200&deg; C. and at most 350&deg; C., and surface hardness after tempering process is at least HRC57. Thus, an inexpensive heat resistant carburized rolling bearing component and manufacturing method thereof can be obtained, which realizes superior rolling fatigue life, wear resistance and dimensional stability under the environment involving foreign matters and high temperature.

Heat resistant carburized rolling bearing component and manufacturing method thereof

A steel for a large bearing suitable for parts of a large-sized bearing which are excellent in resistance to breakage and rolling fatigue life characteristics, and having a chemical composition by mass percentage of 0.80 to 1.30% of C, more than 0.35% and not more than 0.80% of Si, 0.30 to 0.90% of Mn, 0.90 to 1.50% of Cr, one or both of not more than 0.25% of Mo and 0.20 to 1.50% of Ni, the remainder being Fe and inevitable impurities, and exhibiting the following quench-hardenability measured according to a method specified in JIS G 0561: a HRC of 64 or more at J 1.5 mm, a HRC of 63 to 66 at J 7 mm, a HRC of 37 to 50 at J 15 mm, a HRC of 30 to 45 at J 20 mm, a HRC of 28 to 38 at J 45 mm.

Steel for large bearing and parts for large bearing

A high bearing pressure-resistant member used as a rolling element forming part of a toroidal continuously variable transmission for an automotive vehicle. The high bearing pressure-resistant member is formed of a mechanical structural steel containing Cr. The mechanical structural steel includes a matrix having at least one of martensite structure and bainite structure. The matrix contains carbide having a mean particle size of 3 &mgr;m or less, dispersed and precipitated in form of at least one of generally spheres and pseudo-spheres.

High bearing pressure-resistant member

A steel product contains, by mass %, C: 0.45 to 0.60%, Si: 0.01 to 0.15%, Mn: 0.20 to 0.60%, S: 0.012% or lower, Al: 0.015 to 0.040%, Ti: 0.005 to 0.050%, B: 0.0005 to 0.0050%, N: 0.010% or lower, O: 0.0010% or lower, and balance being Fe and unavoidable impurities. Limitations are provided to allowable maximum sizes per each sort of contained non-metallic inclusions and the number per unit area thereof. This steel may contains one kind or two kinds or more of Cr: 1.00% or lower, Mo: 0.50% or lower and Ni: 1.50 or lower.

Steel for induction quenching and machinery structural parts using the same

Bearing steel materials that are superior in cold workability, machinability, hardenability and rolling contact fatigue life are provided. During the processing of steel materials, the generation of large carbides, that detrimentally affect the rolling contact fatigue life of the steel, is inhibited, thereby obviating the necessity of a heat treatment for dissolving the carbides. The present steel material contains the following alloy elements in percentage by mass: 0.55% to 0.82% of carbon; 0.05% to 0.20% of silicon; 0.50% or less of manganese; 0.90% to 1.30% of chromium; 0.05% to 0.30% of molybdenum; and the remaining percentage substantially of iron. After the spheroidizing annealing of the steel material, the total cross-sectional area rate of carbide is 25% or less.

Steel composition for bearings and method of producing the same

A steel for gears consists essentially of 0.10-0.30 wt % of C, not more than 1.0 wt % of Si, not more than 1.0 wt % of Mn, 1.50-5.0 wt % of Cr, and balance including iron and impurity. A gear made by the steel forms a hardened surface layer by carbonizing-hardening-tempering or carbonitriding-hardening-tempering. The amount of C at the hardened surface layer is within a range 0.7 to 1.3 wt %, and the amounts of C, Si and Cr satisfies a relationship 5.5&lt;3.times.C (wt %)+5.2.times.Si (wt %)+Cr (wt %). Therefore, the gear performs superior pitting-resistance and wear-resistance.

Steel for gear, gear superior in strength of tooth surface and method

A steel shaft material having desirable cuttability and induction hardenability even in the form of milled stock without being subjected to any heat treatment, such as annealing, and a method for manufacturing the same. A steel ingot is prepared containing 0.38 to 0.45 wt. % of carbon, 0.15 wt % or less of silicon, 0.3 to 1.0 wt % of manganese, 0.0005 to 0.0030 wt % of boron, 0.01 to 0.05 wt % of titanium, 0.01 to 0.06 wt % of aluminum, 0.010 wt % or less of nitrogen, optionally at least one of chromium in an amount of 0.3 wt % or less and molybdenum in an amount of 0.10 wt % or less, and optionally at least one of 0.005 to 0.30 wt % of sulfur, 0.0002 to 0.005 wt % of calcium, 0.005 to 0.30 wt % of lead and 0.005 to 0.10 wt % of tellurium, and the remainder being iron and unavoidable impurities. After the ingot is heated to 1,100.degree. C. or less, the ingot is milled at a finishing temperature of 950.degree. C. or below and an area reduction rate of 70% or higher, and then cooled in the atmosphere. The steel material of the present invention has a microstructure formed of ferrite and lamellar pearlite (the amount which remains bainite being %5 or less) and having a ferrite grain size number of 6 or higher, as determined by JISG0552, a HRB hardness of 80 to 90, as determined by JISZ2245, and a DM-T decarbonized depth of 0.20 mm or less, as determined by JISG0558.

Steel shaft material which is capable of being directly cut and

A non-heat refining steel having a high fatigue strength in addition to an excellent machinability, which consists essentially of 0.30-0.50 wt % of C, 0.35-0.70 wt % of Si, 0.80-1.40 wt % of Mn, 0.30-0.80 wt % of Cr, 0.05-0.35 wt % of V, not more than 0.15 wt % of S and not more than 0.35 wt % of Pb so that (S+Pb) is not less than 0.06 wt % and (S+Pb/4) is not more than 0.15 wt %, 0.0003 to 0.0050 wt % of Ca, not more than 0.010 wt % of Al, 0.0015-0.0030 wt % of O and the balance of being Fe and inevitable impurities, and has a micro-structure composed of 10 to 40% by area of ferrite and balanced pearlite after hot working and air cooling.

High strength non-heat refining free cutting steels

A free-cutting Ti alloy is disclosed. The basic alloy composition of this free-cutting Ti alloy essentially consists of at least one of S: 0.001-10%, Se: 0.001-10% and Te: 0.001-10%; REM: 0.01-10%; and one or both of Ca: 0.001-10% and B: 0.005-5%; and the balance substantially Ti. The Ti alloy includes one or more of Ti-S (Se, Te) compounds, Ca-S (Se, Te) compounds, REM-S (Se, Te) compounds and their complex compounds as inclusions to improve machinability. Some optional elements can be added to above basic composition. Also disclosed are methods of producing the above free-cutting Ti alloy and a specific Ti alloy which is a particularly suitable material for connecting rods.

Free-cutting Ti alloy

Sulfur-containing free-cutting steel may have an improved machinability and fewer defects by adding certain amounts of Te, Pb and Bi to prevent elongation of sulfide inclusion particles, and by lowering Al-content to decrease Al.sub.2 O.sub.3 of oxide inclusions or by lowering O-content to decrease large Al.sub.2 O.sub.3 inclusion particles. The free-cutting steel may be produced by continuous casting.

Free cutting steel

Mechanical anisotropy of a free cutting steel having excellent machinability can be effectively decreased by controlling inclusions so that the steel may contain inclusion A which softens at a temperature below 1000.degree. C. and inclusion B which has a melting point above 1300.degree. C. but exhibits plasticity at a temperature between 900.degree. and 1300.degree. C., that the inclusion A and the inclusion B may exist in a mutually adhered form, and that the areal percentage of the inclusion A may be at least 1% of areal percentage of the inclusion B. Typical compositions of the inclusion A are: Pb, Bi, MnS--MnTe, SiO.sub.2 --K.sub.2 O, SiO.sub.2 --Na.sub.2 O, SiO.sub.2 --K.sub.2 O--Al.sub.2 O.sub.3, SiO.sub.2 --Na.sub.2 O--Al.sub.2 O.sub.3 and SiO.sub.2 --Na.sub.2 O--CaO--MnO; and typical compositions of the inclusion B are: MnS, MnSe and Mn(S,Se).

Free cutting steel containing controlled inclusions and the method of

A steel for cold forging containing C up to 0.6%, Si up to 0.5%, Mn up to 2.0%, S 0.003 to 0.04% and Te up to 0.03%, wherein ratio %Te/%S being at least 0.04, and further, Al up to 0.04%, N up to 0.02% and O up to 0.0030%, and the balance being substantially Fe exhibits both good formability in cold forging and good machinability. The steel may further contain one or more of additional alloying elements selected from the group of Ni, Cr and Mo, the group of V, Nb, Ti, B and Zr, and the group of Pb, Se, Bi and Ca. The steel for cold forging having good machinability is made preferably by agitating molten steel containing adjusted amounts of the alloying elements other than Te, and, if used, members of the Pb group, by introducing non-oxidizing gas thereinto so as to float up and separate large sized particles of non-metallic inclusions, and subsequently adding predetermined amount of Te and other elements.

Steel for cold forging having good machinability and the method of

A free cutting steel for machine structural use containing C up to 0.6%, Si up to 2.0%, Mn up to 2.0%, S 0.04 to 0.4%, Te 0.002 to 0.5% and O 0.0010 0.0300%, the balance being substantially Fe exhibits excellent machinability when the MnS-based inclusion is in the form of particles of 5 to 100.mu. long, 1 to 10.mu. wide, wherein the aspect ratio length/width is not larger than 10, and at the density of 20 to 200 particles per 1 mm.sup.2 of the matrix cross section. A free cutting steel for machine structural use containing C up to 0.6%, Si up to 2.0%, Mn up to 2.0%, S 0.04 to 0.4% and Te up to 0.1%, wherein %Te/%S is at least 0.04, O up to 0.003% and N up to 0.0200%, the balance being substantially Fe exhibits improved rolling-contact fatique strength when at least 80% of sulfide-based inclusion particles of 10.mu. long or more have the aspect ratio length/width of 5 or less, and when areal percentage of alumina cluster in the matrix cross section is not higher than 0.5%.

Free cutting steel containing sulfide inclusion particles with

Machinable ferrite stainless steels having an excellent corrosion resistance, consisting of not more than 0.030% of C, not more than 0.050% of N, not more than 0.012% of O, not more than 0.8% of Si, not more than 1.6% of Mn, 0.05-0.40% of S, 16-22% of Cr, and 1-3% of Mo, or at least one of 0.03-0.25% of Pb, 0.03-0.20% of Se and 0.01-0.15% of Te, the remainder being Fe, provided that the sum of C and N is not more than 0.060% and Mn/S is 2-5, characterized by that Cr content based on 100 parts by weight of sulfide inclusions formed in the said steels is 10-50 parts by weight.

Machinable ferrite stainless steels

Growing community of inventors

Mie, Japan

Sadayuki Nakamura