The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Oct. 14, 1980
Filed:
Nov. 27, 1978
Toshiyuki Watanabe, Nishio, JP;
Hisao Kamiya, Kariya, JP;
Noriyoshi Shibata, Chita, JP;
Takayoshi Shimizu, Tokai, JP;
Daido Seiko Kabushiki Kaisha, Nagoya, JP;
Abstract
A steel which is suitable for the material of a mold used for plastic molding and which has an improved resistance to corrosion under exposure to a halogen gas generated in injection molding of a thermoplastic synthetic resin blended with a halogen-containing flame-retarding agent is obtained by shaping a steel which consists essentially of up to 0.05% carbon, up to 1.0% silicon, up to 2.0% manganese, 5.0-8.0% nickel, 11.0-15.0% chromium, 1.0-4.0% molybdenum, 0.5-4.0% copper, 0.5-2.0% cobalt and the balance iron into a mold, and then subjecting the mold to age-hardening treatment at a temperature in the range of 400.degree.-450.degree. C. to obtain a hardness of H.sub.R C 30 or higher. The steel may further contain a small, predetermined amount of at least one machinability-improving component such as lead, tellurium, calcium and bismuth and/or a small, predetermined amount of at least one toughness or hardness-improving component such as tungsten, boron, titanium, vanadium, niobium and tantalum.