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Patent Searching and Data


Title:
BOLT
Document Type and Number:
WIPO Patent Application WO/2019/150434
Kind Code:
A1
Abstract:
The bolt according to the present invention is a high-carbon steel and high-strength bolt which has a tempered martensite texture and the composition of which comprises: 0.50-0.65 mass% inclusive of carbon (C); 1.5-2.5 mass% inclusive of silicon (Si); 1.0-2.0 mass% inclusive of chromium (Cr); 0.2-1.0 mass% inclusive of manganese (Mn); 1.5-5.0 mass% inclusive of molybdenum (Mo); not more than 0.03 mass% of phosphorus (P) and sulfur (S) in total as impurities; and the balance iron (Fe). In this bolt, the carbon concentration satisfies requirement (1) and an increase in the martensitic transformation start temperature (Ms point) in the surface side is suppressed, which brings about a low susceptibility to hardening crack and excellent delayed fracture resistance. Requirement (1): 0.75≤X<1 [wherein X represents surface carbon concentration/internal carbon concentration].

Inventors:
HAMADA,Takahiro (Intellectual Property Department, 1-1, Morinosatoaoyama, Atsugi-sh, Kanagawa 23, 〒2430123, JP)
KOBAYASHI,Daisuke (Intellectual Property Department, 1-1, Morinosatoaoyama, Atsugi-sh, Kanagawa 23, 〒2430123, JP)
Application Number:
JP2018/002983
Publication Date:
August 08, 2019
Filing Date:
January 30, 2018
Export Citation:
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Assignee:
NISSAN MOTOR CO., LTD. (2 Takara-cho, Kanagawa-ku Yokohama-sh, Kanagawa 23, 〒2210023, JP)
International Classes:
C22C38/00; C21D9/00; C22C38/34; F16B35/00
Domestic Patent References:
WO2016031528A12016-03-03
Foreign References:
JP2012233244A2012-11-29
JPH10141341A1998-05-26
JPS6452045A1989-02-28
JPH11199922A1999-07-27
Attorney, Agent or Firm:
MATOBA, MOTONORI (MR Building 3F 30-17, Hongo 1-chome, Bunkyo-k, Tokyo 33, 〒1130033, JP)
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