Nippon Steel Corporation

Nippon Steel Sumitomo Metal Corporation

Teruaki Yamada

Osamu Akisue

Kiyokazu Ishizuka

Teruki Hayashida

Hidetoshi Shindou

Kiyokazu Isizuka

Toshiyasu Ukena

Kaoru Kawasaki

Kazuo Takahashi

Munetsugu Matsuo

Masato Yamada

Ikuo Kikuchi

Junji Haji

Kimitaka Hayashi

Daisuke Ito

Yoshikuni Tokunaga

Masahiko Oda

Kohji Miyoshi

Kenji Kawai

Yuuji Sano

Michihiro Nouno

Norimasa Uehara

Shigeru Ueda

Shigekazu Ooba

Keiichi Sanada

The present invention provides a method of production of hot dip galvannealed steel sheet with excellent workability compared with the Sendzimir method or non-oxidizing furnace method and further with excellent powdering or slidability, that is, a method of production of hot dip galvannealed steel sheet with excellent workability, powdering, and slidability characterized by processing a slab containing, by mass %, C: 0.01 to 0.12%, Mn: 0.05 to 0.6%, Si: 0.002 to 0.1%, P: 0.05% or less, S: 0.03% or less, sol. Al: 0.005 to 0.1%, and N: 0.01% or less and having a balance of Fe and unavoidable impurities by hot rolling, pickling, cold rolling, then annealing at 650 to 900&#xb0; C., cooling to 250 to 450&#xb0; C., holding at said temperature range for 120 seconds or more, then cooling to room temperature, pickling, preplating Ni or Ni&#x2014;Fe without intermediate temper rolling, heating by 5&#xb0; C./sec or more down to 430 to 500&#xb0; C., galvanizing in a galvanization bath, wiping, then heating by a rate of temperature rise of 20&#xb0; C./sec or more up to 460 to 550&#xb0; C., not providing any soaking time or holding for soaking for less than 5 seconds, then cooling by 3&#xb0; C./sec or more, and final temper rolling by a 0.4 to 2% elongation rate.

Method of production of hot dip galvannealed steel sheet with excellent workability, powderability, and slidability

Disclosed is a battery can for a storage battery, provided with a safety valve having a first and a second score groove portion is provided to inner and outer surface of can bottom, can body, or can lid. The first and the second score groove portion face each other, and have a first and a second score groove bottom portion, which have a radius of curvature R, respectively. The R is more than 0.20 mm and less than 1.20 mm, and a distance between the bottom portions is 0.045 to 0.150 mm. The portion, which has the safety valve, is constituted by a plated steel sheet having a steel sheet portion of C content is less than 0.040 mass %, S content is less than 0.020 mass %, and tensile strength TS is less than 400 MPa, and a plate layer formed on a surface of the steel sheet portion.

Battery can for storage battery

The present invention provides a steel sheet material used for a positive electrode can and a positive electrode can for an alkaline manganese battery capable of improving the battery characteristics for an alkaline manganese battery, characterized in that the plated steel sheet for a positive electrode can for an alkaline manganese battery has Ni-based diffusion plating layer having on the top layer many small pinholes of diameter not greater than 1 &#x3bc;m, i.e. submicron pinholes, formed on the surface of the steel sheet to be used as an internal surface of the can. Said submicron pinholes preferably have, as observed by SEM, diameter in the range of 0.1&#x2dc;1 &#x3bc;m and are present at density not less than 30 pcs/(10 &#x3bc;m&#xd7;10 &#x3bc;m). The surface of the steel sheet to be used as an external surface of the can preferably has a Fe&#x2014;Ni diffusion plating layer and a Ni plating layer that has been softened by recrystallization.

Ni-plated steel plate for alkali-manganese dry cell anode can and alkali-manganese dry cell anode can

The aim of the present invention is to provide a phosphate treated zinc coated steel sheet with excellent workability. A steel sheet coated with a zinc based alloy has a phosphate treated coating on the surface thereof. The phosphate treated coating comprises mainly granulated crystals, specifically, crystals in which the average ratio of the major axis to the minor axis is not less than 1.00 and not more than 2.90. Moreover, the method for producing the phosphate treated coating uses a phosphate treatment solution in which the amount of Mg ions is &gE;6 g/l and the amount of Zn ions is &gE;0.5 g/l, or a phosphate treatment solution in which the amount of Mg ions is &gE;10 g/l, the amount of Zn ions is 0&lE; and <0.5 g/l, and the amount of nitric acid ions is &gE;40 g/l. Moreover, the phosphate treated zinc coated steel sheet also has excellent corrosion resistance as the amount of Mg in the phosphate treated coating is not less than 10 mg/m , and has excellent weldability as the coating amount is controlled to 0.5 to 3.0 g/m .

Zinc-based metal plated steel sheet treated with phosphate being excellent in formability and method for production thereof

The present invention aims at provision of an organic composite galvanized steel sheet having its characteristics such as corrosion resistance and workability improved. Thus, the present invention provides an organic composite galvanized steel sheet that is formed by sequentially depositing on a surface of a steel sheet a galvanization layer, a zinc phosphate layer containing Mg, and an organic layer, and is characterized in that a value of Mg/P (weight ratio) in the zinc phosphate layer is 0.15 or larger and an amount of Mg contained in the zinc phosphate layer is 20 mg/m or more. Preferably, the zinc phosphate layer contains one or two or more of Ni, Mn, Co, Fe, Cu, Al, and Ca. In one preferred embodiment, the organic layer is formed as a composite layer containing an organic resin and one or two kinds or more of powder or colloid selected from SiO , Al O , MgO, Fe O , Fe O , ZrO , TiO , and SnO .

Organic composite coated zinc-based metal plated steel sheet

A zinc-plated steel sheet with an ageing resistance is produced from an Al-killed steel by hot dip type, continuous zinc plating including recrystallization and annealing, where after recrystallization and grain growth, the steel sheet is quenched at a cooling rate of 30.degree..about.250.degree. C/sec from 720.degree..about.600.degree. C. to 310.degree..about.200.degree. C.; after keeping the steel sheet at the same temperature for 0 to 15 seconds, the steel sheet is reheated to a molten zinc bath temperature; then the steel sheet is dipped into the molten zinc bath for zinc-plating; and then the steel sheet is cooled at a cooling rate of 250 to 5.degree. C./sec from that temperature to 350.degree. C.; and then the steel sheet is cooled at a specific average cooling rate in a temperature region of 350.degree. C. to 300.degree. C. and at a specific average cooling rate in a temperature region of from 300.degree. C. to 285.degree..about.220.degree. C.

Process for producing a zinc-plated steel sheet with an ageing

A cold rolled steel sheet having a good ageing resistance is produced by subjecting a cold rolled steel sheet to continuous annealing including recrystallization, grain growth, quenching, supercooling, reheating and overageing according to inclinatory cooling, where after the recrystallization and the grain growth, the steel sheet is quenched at a cooling rate of 50 to 250.degree. C./sec from 720-600.degree. C. to 200-310.degree. C.; after retaining the steel sheet at the same temperature for 0 to 15 seconds, the steel sheet is reheated by at least 40.degree. C. up to 320-400.degree. C.; then the steel sheet is retained at the same temperature or cooled at a rate of not more than 0.7.degree. C./sec including the time for retaining the steel sheet at the same temperature; and then the steel sheet is cooled at an average cooling rate of not more than 10.degree. C./sec in a temperature zone of higher than 350.degree. C., at a specific average cooling rate in a temperature zone of 350.degree. C. to 300.degree. C. and at a specific average cooling rate down to 285-220.degree. C. in a temperature zone of lower than 300.degree. C.

Process for producing a cold rolled steel sheet having a good ageing

Disclosed is a process for producing titanium-containing cold rolled steel sheets and strips which can stand very severe press forming, which process comprising hot rolling, coiling at a temperature not lower than 700.degree. C., cold rolling and continuous annealing at a temperature, from 700.degree. to 900.degree. C., for 20 seconds to 2 minutes.

Process for producing deep-drawing cold rolled steel sheets and strips

A method of producing a non-ageing cold rolled steel strip having excellent deep-drawability, with a r value of 1.5 or higher and ageing index of not higher than 3 kg/mm.sup.2 from an Al-killed steel with a lowered carbon content between 0.001 and 0.0035% and with no special additives such as titanium by a relatively low temperature coiling in the hot rolling, and a short-time continuous annealing without over-ageing, thus over-coming the disadvantages caused by a high temperature coiling and by additional over-ageing.

Method of producing non-ageing cold rolled steel strip with excellent

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Himeji, Japan

Teruaki Yamada