Kawasaki Steel Corporation

Research Development Corporation

Solex Research Corporation of Japan

Yoshio Nakazato

Minoru Hoshino

Fumiya Yanagishima

Toko Teshiba

Kazuhiro Uchino

Toshio Watanabe

Hidenori Miyake

Yo Ito

Koichi Hashiguchi

Akira Kishida

Tomoo Tanaka

Nobuo Ohashi

Akira Yamamoto

Naohiko Soeda

Kanji I

Noboru Ishihara

Masatoshi Nakazawa

Shunji Fujiwara

A metal stripping system and an operation process therefor which includes the following elements and steps. A main part of this system is a crystallization apparatus for metal stripping comprising a mixing zone of organic solvent and fluoride series stripping solution, a settling zone for organic solvent, a settling zone for stripping solution, a separation zone for fluorinated metal complex crystal and a stripping solution cooling zone. In the operation of the system wherein the organic solvent containing extracted metal ions is contacted with the fluoride series stripping solution to deposit the fluorinated metal complex crystal and then the crystal is recovered as metal or metal oxide, the stripping solution is circularly used by supplying NH.sub.4 HF.sub.2 solution to the cooling zone, supplying the stripping solution discharged from the apparatus and absorbed with a decomposition gas of the crystal to the mixing zone, and supplying a filtrate after the crystal separation to the settling zone for stripping solution.

Metal stripping system and an operation process therefor

A method and an apparatus for rolling metal strips by a tandem cold rolling mill. The strip is periodically swung in its width directions at a location upstream of the tandem rolling mill, to bring the strip into contact with rolls of the tandem cold rolling mill over areas of the rolls as widely as possible, thereby preventing irregular wears of the rolls to make it possible to produce defect-free metal strips.

Rolling method and rolling apparatus for metal strips

A method of coiling a thin strip on a tension reel, which comprises coiling a strip rolled to a thickness of not more than 0.3 mm through a last stand of a cold tandem mill at different values of delivery side tension of the last stand and coiling tension produced by arranging a tension control means between the last stand and the tension reel.

Method of coiling thin strips

A process for treating and recovering pickling waste liquids used for the pickling of stainless steel such as nitric-hydrofluoric acid, nitric acid, hydrochloric acid and, sulfuric acid is disclosed, which comprises recovering the nitric-hydrofluoric acid and the iron oxide or metallic ion from the waste liquids of nitric-hydrofluoric acid and nitric acid by two solvent extraction processes and recovering the Cr and Ni containing ferrite from the waste liquids of sulfuric acid or hydrochloric acid by a ferrite formation process. When the waste acid is sulfuric acid, gypsum of a high purity can be obtained.

Process for treating and recovering pickling waste liquids for stainless

High tensile strength steel sheets having high press formability and excellent shape-fixability in which an average roughness in surface Ha is 0.4-1.8 .mu.m, PPI value is more than 80 at a cut off level of 0.5 .mu.m, the proportional limit stress is less than 20 kg/mm.sup.2 and the microstructure consists of ferrite grains dispersed with fine martensite islands, are produced by cold rolling a hot rolled steel sheet containing 0.005-0.15% of carbon, and manganese, if necessary boron, molybdenum, chromium, silicon, nickel and copper within a range of 0.27-3% of Mneq. shown by the following formula (1)

High tensile strength steel sheets having high press-formability and a

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.

Hot-rolled low-carbon steel strip with an excellent press-workability

Growing community of inventors

Chiba, Japan

Yoshio Nakazato