Kawasaki Steel Corporation

Kao Corporation

Kawatetsu Wire Products Company Ltd.

Hideo Abe

Susumu Satoh

Toru Sasaki

Toshiyuki Kato

Takaaki Hira

Keiji Nishimura

Saiji Matsuoka

Kazuhito Kenmochi

Susumu Okada

Kazunori Osawa

Michio Yamashita

Ikuo Yarita

Yuji Shimoyama

Fumiya Yanagishima

Hiroyuki Nagamori

Yoshio Yamazaki

Yoshiharu Daikuzono

Takeshi Yoshimoto

Hiroyuki Matsuda

Nobuo Tomizawa

Makoto Kobayashi

Hiroshi Yoshida

Takashi Obara

Hideki Watanabe

Norio Takashima

Kozo Tsunoyama

Kunio Isobe

Akira Torao

Kusuo Furukawa

Akira Kishida

Masanori Kitahama

Hiroaki Sasaki

Norio Ohta

Koichi Ito

Akihiko Fukuhara

Tomio Komatu

Takashi Kusaba

Takayuki Yanagimoto

Takaaki Iguchi

Tsuneo Nagamine

Shuji Watanabe

Kunihiko Kataoka

Shingo Emi

Tojiro Ikeda

Jun-ichi Mano

Kichizaemon Nakagawa

Toshiyuki Katoh

Kouichi Tahara

Singo Emi

Takashi Sasaki

Keiji Kumagai

Takanori Tamari

Nobuhiko Uesugi

In a pipe forming process using bending rolls, load applied to an upper roll is reduced to suppress the deflection of the upper roll, thereby suppressing creation of large end gap at the longitudinal center of the pipe, thus enabling production of high-strength, thick-walled elongated pipes. This is achieved either by (1) setting the roll spacing L between lower rolls to a value greater than the sum of the diameter Dwu of the upper roll and the diameter Dwl of each of the lower rolls , and setting the amount S of tightening of the upper roll with respect to the lower rolls to a value greater than the radius Rwl of each of the plural rolls; or by (2) effecting pipe forming work on the sheet material such that the spacing L of the lower rolls satisfies the following condition: (Dp&plus;Dwl)>L&gE;0.85(Dp&plus;Dwl), where Dp represents the outside diameter of the product pipe and Dwl represents the diameter of one of the plural rolls; or by (3) preparing the sheet material having leading and trailing bent end regions bent beforehand over a length not smaller than &frac15; of the entire circumference of the pipe to be produced; and effecting bending by the bending rolls such that the length of the regions bent by the bending rolls is less than &frac35; the entire circumference of the pipe.

Pipe formed by bending rolls

Pipe forming apparatus and method

A steel sheet for porcelain enameling having improved press formability and enameling properties comprises particular amounts of C, Mn, B, Cu, Al, O, N, and P or further Ti and Nb and the balance being Fe and inevitable impurities and is produced by hot rolling a slab of steel having a chemical composition as mentioned above as a starting material, cold rolling the resulting hot rolled sheet at a reduction of not less than 70%, and then subjecting the resulting cold rolled sheet to a continuous annealing at a heating temperature of not lower than 800.degree. C. but not higher than A.sub.c3 transformation point.

Steel sheets for procelain enameling and method of producing the same

A method of producing a high-strength cold-rolled steel sheet suitable for working uses which utilizes a steel material having the following composition: not more than 0.006 wt % of C, not more than 0.5 wt % of Si, not more than 2.0 wt % of Mn, and not less than 0.01 wt % but not more than 0.10 wt % of Ti, the Ti, C and N contents being determined to meet the condition of Ti&gt;(48/12) C wt %+(48/14) N wt %, the steel also consisting essentially of not less than 0.0010 wt % but not more than 0.0100 wt % of Nb, not less than 0.0002 wt % but not more than 0.0020 wt % of B, not less than 0.03 wt % but not more than 0.20 wt % of P, not more than 0.03 wt % of S, not less than 0.010 wt % but not more than 0.100 wt % of Al, not more than 0.008 wt % of N, not more than 0.0045 wt % of O, and the balance substantially Fe and incidental inclusions. The steel material is cast and hot-rolled and then subjected to a cold rolling conducted at a sheet temperature not higher than 300.degree. C. under such a condition that the sum of the rolling reductions of passes which meet the following condition between said sheet temperature (T .degree.C.) and the strain rate .epsilon. (S-1) is 50% or greater:

Method of producing high-strength cold-rolled steel sheet suitable for

A formable thin steel sheet such as hot rolled sheet, cold rolled sheet or surface treated sheet comprises not more than 0.003 wt % of C, not more than 1.0 wt % of Si, not more than 1.0 wt % of Mn, not more than 0.15 wt % of P, not more than 0.020 wt % of S, not more than 0.0045 wt % of O, not more than 0.0020 wt % of N, not more than 0.15 wt % of Al provided that a ratio of Al/N is not less than 30, and the balance being Fe and inevitable impurities, and has not only improved formability for press forming, deep drawing or the like but also improved fatigue resistance as a welded joint.

Method of producing formable thin steel sheets

Method of producing steel sheets for porcelain enameling having improved

Method of producing steel sheets for porcelain enameling and the same

A formable thin steel sheet such as hot rolled sheet, cold rolled sheet or surface treated sheet comprises not more than 0.003 wt. % of C, not more than 1.0 wt % of Si, not more than 1.0 wt % of Mn, not more than 0.15 wt % of P, not more than 0.020 wt % of S, not more than 0.0045 wt % of O, not more than 0.0020 wt % of N, not more than 0.15 wt % of Al provided that a ratio of Al/N is not less than 30, and the balance being Fe and inevitable impurities, and has not only improved formability for press forming, deep drawing or the like but also improved fatigue resistance as a welded joint.

Formable thin steel sheets

A cold-rolled steel sheet suitable for deep drawing has a composition containing up to about 0.005 wt % of C, up to about 0.1 wt % of Si, up to about 1.0 wt % of Mn, up to about 0.1 wt % of P, up to about 0.05 wt % of S, about 0.01 to 0.10 wt % of Al, up to about 0.005 wt % of N, one, two or more elements selected from the group consisting of about 0.01 to 0.15 wt % of Ti, about 0.001 to 0.05 wt % of Nb and about 0.0001 to 0.0020 wt % of B, and the balance substantially Fe and incidental impurities. The steel sheet exhibits a Lankford value (r-value) of about r.gtoreq.2.8 and also exhibits the difference (r.sub.max -r.sub.min) between the maximum value r.sub.max and the minimum value r.sub.min satisfying the condition of (r.sub.max -r.sub.min).ltoreq.about 0.5. The steel sheet is produced by a process having the steps of: conducting hot-rolling on the steel material of the above-described composition; conducting a primary cold rolling at a rolling reduction not smaller than about 30%; conducting intermediate annealing at a temperature ranging between the recrystallization temperature and about 920.degree.; conducting secondary cold rolling at a rolling reduction not smaller than about 30% so as to provide a total rolling reduction not smaller than about 78%; and conducting final annealing at a temperature which is between the recrystallization temperature and about 920.degree. C.

Cold-rolled steel sheet for deep drawing and method of producing the same

A method of manufacturing a steel sheet having excellent deep-drawability. A steel blank is rolled into a steel sheet having a predetermined thickness. The steel contains C: not more than 0.008 wt %, Si: not more than 0.5 wt %, Mn: not more than 1.0 wt %, P: not more than 0.15 wt %, S: not more than 0.02 wt %, Al: 0.010 to 0.10 wt %, N: not more than 0.008 wt %, and at least one element selected from the group consisting of Ti and Nb which is contained in an amount satisfying the relationship of 1.2 (C/12+N/14).ltoreq.(Ti/48+Nb/93). In at least one pass, rolling is conducted within a temperatures range lower than the Ar3 transformation point but not lower than 500.degree. C., in such a manner that the roll radius R (mm) and the blank thickness t (mm) before rolling by rolls satisfy the relationships of R.ltoreq.200 and R.sup.2 .times..sqroot.t.ltoreq.100000, and the total rolling reduction at temperature lower than the Ar3 transformation point is not lower than 60%. The hot-rolled steel sheet possesses a high level of Lankford value, and is free from cold-working embrittlement. The method may include the step of obtaining, after the rolling, pickling, annealing and hot dip galvanizing under certain conditions, a surface-treated steel sheet having excellent deep-drawability.

Method of manufacturing steel sheet having excellent deep-drawability

A process and an equipment for micro-pattern forming on the surface of a rolling roll, and a metallic thin sheet and preparation thereof by transferring a micro-pattern on the surface by use of the roll are provided. Such a rolling roll can be attained by a method wherein resin film mixed with optical absorbing agent is formed on the surface, a Q switch YAG laser having an output of 5 to 100W is applied to make a marking on this resin film, a part of the coated film is removed in strict accordance with the pattern, then an etching process is applied to the roll surface. The metallic thin sheet skin pass rolled by this roll is used as a car panel and is superior in pressworkability and sharpness of reflections.

Process and equipment for micro-pattern forming on roll surface, metal

A process of producing cold rolled stainless steel strip, according to the invention, includes preliminary treatment for hot rolled stainless steel strip, in which preliminary treatment, hot rolled stainless steel strip is, at first, treated through annealing and picking process and is subsequently subject cold rolling without introducing rolling mill lubricant at a reduction of more than 5%. The process of preliminary treatment for preparation of cold rolling is useful for producing high surface brightness cold rolled stainless steel strip, which can achieve both of satisfactory quality and high efficiency.

Method and apparatus for preliminary treatment of stainless steel for

A work roll has a regularly and geometrically patterned uneven dulled section on the roll surface. Eavh uneven dulled section is composed of a crest and concavity and is of crater-like configuration. In order to obtain good performance in temper rolling, the crest is in a form of an annular ring extending around the edge of the concavity. According to the invention, pattern of arrangement of the uneven dulled sections is determined in relation to the diameter of the ring-shaped crests of the uneven dulled section so as to obtain optimum performance in producing good quality, exhibiting substantially high image clarify as coated by paint, enamel or so forth.

Work roll with dulled surface having geometrically patterned uneven

Thin steel sheets having an improved processability are produced when a steel sheet or cast strip obtained through a continuous casting or strip caster process is subjected to a lubrication rolling step at a temperature of from Ar.sub.3 transformation point to 300.degree. C. and a rolling speed of not less than 1,500 m/min. By this method, the cold rolling step or cold rolling-annealing step can be omitted.

Method of producing thin steel sheets having an improved processability

A cold-rolling lube oil for metallic materials is composed of (a) 40-90 wt. % of a monoester of a specific aliphatic carboxylic acid and a particular aliphatic alcohol, (b) 0.5-10 wt. % of at least one of dimer acids and polymer acids of certain unsaturated higher fatty acids, (c) 10-25 wt. % of a fats and fatty oils, or 5-70 wt. % of an ester obtained by reacting remaining carboxyl or hydroxyl groups of a specific polyester with a specific alcohol or fatty acid, (d) 0.3-10 wt. % of a phenol-type antioxidant, and (e) 0.3-10 wt. % of a sulfur-type antioxidant.

Cold-rolling lube oil for metallic materials

Growing community of inventors

Chiba, Japan

Hideo Abe