Kawasaki Steel Corporation

Other

Mitsubishi Heavy Industries Limited

Mitsubishi Jukogyo Kabushiki Kaisha

Osamu Hashimoto

Susumu Sato

Toshio Irie

Susumu Satoh

Takashi Obara

Masahiko Morita

Hideo Suzuki

Minoru Nishida

Tomoo Tanaka

Yasushi Kato

Kenji Nishikawa

Kenichi Yanagi

Kazuo Morimoto

Sachihiro Iida

Keiichi Yoshioka

Shinjiro Murakami

Takeo Fukushima

Kaneaki Hyodo

Katsumi Makihara

Yoshihito Hiraiwa

Nobuo Matsuno

A projecting portion which becomes convex in radial direction is formed in a rubber elastic body for connecting together an inner cylindrical body mounted to a shaft portion of a lower shift lever member by external interfit and an outer cylindrical body mounted to a cylindrical portion of an upper shift lever member by internal interfit. Formed in an inner peripheral surface of the outer cylindrical body is a recessed portion which becomes concave with clearances C and C of respective given amounts left between the recessed portion and the projecting portion . This makes it possible to manufacture a shift lever bush having a two-stage spring characteristic at low cost.

Shift lever bush

A method of producing a chromium-containing steel sheet hot-dip plated with aluminum. A steel sheet containing not less than about 3 wt % of chromium is pre-plated at each side thereof with an iron-phosphor alloy so that a pre-plating layer of the iron-phosphor alloy about 0.05 to 3.0 .mu.m thick is formed on each side of the steel sheet. The steel sheet is heated and then subjected to an aluminum hot-dip plating by being dipped in a bath of molten aluminum or a molten aluminum alloy. An undercoat nickel plating layer may be formed on the steel sheet in advance of pre-plating with the iron-phosphor alloy.

Process for producing chromium-containing steel sheet hot-dip plated

The present invention relates to the production of a cold rolled steel sheet having good ageing resistance and small anisotropy and adapted for deep drawing, which properties can satisfy concurrently the demands for the deep drawability and ageing resistance of the cold rolled steel sheet to be pressed and used for automotive exterior plate. The present invention has concurrently and satisfactorily solved the problems in the above described good ageing resistance and anisotropy, which problems had not hitherto been solved in the conventional method, by a method wherein a cold rolled steel sheet having such a limited composition that contains not more than 0.004% of C, 0.002-0.010% of a total amount of at least one element selected from Nb, Ti, V, Zr and W, and further occasionally contains not more than 0.0050% of B, is subjected to a continuous annealing at a temperature within the range of 700-950.degree. C. in the production of the cold rolled steel sheet according to the conventional method. The steel sheet obtained in the present invention can be advantageously used as a thin steel sheet adapted to be pressed, for example, into an automotive exterior plate.

Method of producing a cold rolled steel sheet having a good ageing

A cold rolled dual-phase structure steel sheet having an excellent deep drawability is disclosed, which consists of ferrite phase and low temperature transformation product phase and comprises 0.001-0.008 wt % of C, not more than 1.0 wt % of Si, 0.05-1.8 wt % of Mn, not more than 0.15 wt % of P, 0.01-0.10 wt % of Al, 0.002-0.050 wt % of Nb and 0.0005-0.0050 wt % of B provided that the value of Nb(%)+10B(%) is in a range of 0.010-0.080%, and, if necessary, 0.05-1.00 wt % of Cr and the balance being substantially Fe with inevitable impurities. This steel sheet is manufactured by hot and cold rolling a steel slab with the above chemical composition and continuously annealing the resulting steel sheet in such a manner than the steel sheet is heated and soaked at a temperature from .alpha..fwdarw..gamma. transformation point to 1,000.degree. C. and then cooled at an average cooling rate of not less than 0.5.degree. C./sec but less than 20.degree. C./sec in a temperature range of from the soaking temperature to 750.degree. C., and subsequently at an average cooling rate of not less than 20.degree. C./sec in a temperature range of from 750.degree. C. to not more than 300.degree. C.

Method of making cold rolled dual-phase structure steel sheet having an

Cutting equipment with rules

A system for online-detection of a transformation value and/or a flatness of a steel or a magnetic material includes: an exciting coil disposed at either side of the plate-shaped steel or magnetic material and capable of generating alternating magnetic fluxes by alternating current excitations; two or more detecting coils arranged on the same side as the exciting coil and at positions different in distance from the exciting coil, and mutually induced with the exciting coil; and an arithmetic unit for obtaining the transformation value and the flatness of the steel or the magnetic material or either one of those from a difference between detection signals generated from a difference in values of interlock magnetic fluxes in the respective detecting coils. The transformation value and the flatness of the steel or the flatness of the magnetic material can be detected with high accuracy.

System for online-detection of the transformation value and/or flatness

In controlling the cooling of a hot-rolled steel sheet after hot rolling, a target value of a transformation rate required for obtaining mechanical properties ultimately expected from the hot-rolled steel plate is previously determined, a rate of gamma to alpha transformed fraction of the hot-rolled steel sheet in a section in which the cooling is controlled is detected by transformed fraction detectors, and an elapsed time from the start of cooling is measured to determine the transformation rate of the steel sheet in a cooling stage, the conditions of cooling being controlled so that the transformation rate can coincide with the target value.

Method of controlling cooling of hot-rolled steel sheet and system

The invention concerns cooling apparatus for strip metal of the kind comprising a series of spaced cooling rolls around which the strip metal is passed such that it follows a serpentine path and is cooled by contact with the rolls, and elongate gas jet devices disposed widthwise of the strip opposite the outer surface parts of respective cooling rolls in contact with the strip. The invention is characterized in that each said gas jet device is partitioned into segments in said widthwise direction, in that each segment is provided with a gas flow control valve, in that means are provided at least at one cooling roll position for detecting strip temperature across its width, and in that strip temperature control and arithmetic means are provided to which the gas flow valves and the temperature detecting means are electrically connected, the arrangement being such that the temperature difference between the average temperature across the strip and the temperature of the strip at each segment width position can be compared, via electrical signals from the temperature detecting means and, if the temperature difference at a widthwise position is above or below predetermined limits, the corresponding gas flow control valves are adjusted to bring the temperature within the predetermined limits.

Cooling apparatus for strip metal

A cold rolled dual-phase structure steel sheet having an excellent deep drawability is disclosed, which consists of ferrite phase and low temperature transformation product phase and comprises 0.001-0.008 wt % of C, not more than 1.0 wt % of Si, 0.05-1.8 wt % of Mn, not more than 0.15 wt % of P, 0.01-0.10 wt % of Al, 0.002-0.050 wt % of Nb and 0.0005-0.0050 wt % of B provided that the value of Nb (%)+10B (%) is in a range of 0.010-0.080%, and, if necessary, 0.05-1.00 wt % of Cr and the balance being substantially Fe with inevitable impurities. This steel sheet is manufactured by hot and cold rolling a steel slab with the above chemical composition and continuously annealing the resulting steel sheet in such a manner than the steel sheet is heated and soaked at a temperature from .alpha..fwdarw..gamma. transformation point to 1,000.degree. C. and then cooled at an average cooling rate of not less than 0.5.degree. C./sec but less than 20.degree. C./sec in a temperature range of from the soaking temperature to 750.degree. C., and subsequently at an average cooling rate of not less than 20.degree. C./sec in a temperature range of from 750.degree. C. to not more than 300.degree. C.

Cold rolled dual-phase structure steel sheet having an excellent deep

Process of manufacturing a cold rolled steel sheet having excellent

The present invention provides high tensile strength cold rolled steel sheets having excellent formability, which consist of 0.002-0.015% of C, not more than 1.2% of Si, 0.04-0.8% of Mn, 0.03-0.10% of P, 0.02-0.10% and not less than N%.times.4 of Al, C%.times.3-{C%.times.8+0.020%} of Nb and the remainder being substantially Fe, as the high tensile strength steel sheets which reduce the weight of automobiles and the like. The steel sheet is produced by hot rolling a steel slab having the above described composition to obtain a hot rolled coil, in the hot rolling the total reduction rate being at least 90%, the rolling speed in the finishing rolling being at least 40 m/min and the coiling-up temperature being at least 600.degree. C.; cold rolling the above described hot rolled coil in a conventional process to obtain a cold rolled steel strip having a final gauge; subjecting the above described cold rolled steel strip to a continuous annealing at a temperature of 700.degree.-900.degree. C. for 10 sec-5 min and then cooling the annealed strip to 500.degree. C. at a rate of at least 60.degree. C./min. The steel sheets having the above described composition, except that Si is not more than 0.5%, are suitable for the continuous hot-dip galvanizing.

Method for producing high tensile strength cold rolled steel sheets

A method of cooling band or hoop steels with hollow cooling rolls through which a cooling medium flows to absorb the heat of the steel strips trained about and in contact with the hollow cooling rolls, thereby cooling the steel strips. According to the invention this method is carried out so as to fulfil the following equation (1) with the cooling roll having a diameter D&gt;600 mm when a thickness h of the steel strip is within 0.2.ltoreq.h&lt;0.6 mm,

Method of cooling cold steel strip with cooling rolls

High tensile strength cold rolled steel sheets and high tensile strength

Non-ageing cold rolled steel sheets having a very excellent formability are produced by hot rolling a steel consisting of not more than 0.008% of C, not more than 0.20% of Si, 0.04-0.30% of Mn, not more than 0.03% of P, 0.01-0.10% of Al, a content of Al being more than N%.times.4, not more than 0.02% of S, not more than 0.01% of N, 0.01-0.07% of Nb, a content of Nb being C%.times.3-{C%.times.8+0.02}%, and the remainder being substantially Fe, at a total reduction of not less than 90%, a rolling speed of not less than 40 m/min in the finishing rolling and a finishing temperature of not lower than 830.degree. C., coiling the hot rolled strip at a temperature of 600.degree.-800.degree. C., cold rolling the coiled strip following a conventional manner to obtain a cold rolled strip having final gauge and then continuous annealing or hot-dip galvanizing the cold rolled strip within a temperature range of 700.degree.-900.degree. C. for 10 seconds-5 minutes.

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Chiba, Japan

Osamu Hashimoto