Title:
STEEL-MADE MEMBER HAVING HIGH HARDNESS AND EXCELLENT IN TOUGHNESS AND NUT OF HIGH LOAD BALL SCREW
Document Type and Number:
Japanese Patent JP2018123374
Kind Code:
A
Abstract:
PROBLEM TO BE SOLVED: To provide a steel-made member having high hardness and high toughness, and a nut of a high load ball screw consisting of the steel member.SOLUTION: There are provided a steel-made member containing, by mass%, C:0.90 to 1.20%, Si:0.10 to 1.00%, Mn:0.90 to 2.00%, P:0.025% or less, S:0.25% or less, Cr:0.90 to 1.60%, Al:0.005 to 0.050%, O:0.0015% or less and the balance Fe with inevitable impurities at a hardening tempering state, in which a micro structure is a mixed phase structure of a martensite structure and spheroidized carbide, 90% or more of total cementite is cementite having a surface hardness of 60 to 64 HRC, aspect ratio of 1.5 or less, old austenite grain degree is 9 or more, area percentage of the bainite structure is 15% or less and retained austenite amount is 20 to 30 vol.%, and nut 6 of a high load ball screw consisting of the steel-made member and shown in the Figure 1.SELECTED DRAWING: Figure 1
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Inventors:
HIRATSUKA YUSUKE
TOKOKAGE NORIMASA
MAEJIMA KATSUMI
KOBAYASHI YUTAKA
OGI HIROMASA
TOKOKAGE NORIMASA
MAEJIMA KATSUMI
KOBAYASHI YUTAKA
OGI HIROMASA
Application Number:
JP2017016054A
Publication Date:
August 09, 2018
Filing Date:
January 31, 2017
Export Citation:
Assignee:
SANYO SPECIAL STEEL CO LTD
TSUBAKIMOTO CHAIN CO
TSUBAKIMOTO CHAIN CO
International Classes:
C22C38/00; C22C38/38; F16H25/22; F16H25/24
Domestic Patent References:
| JP2007077432A | 2007-03-29 | |||
| JP2001152252A | 2001-06-05 | |||
| JP2008088478A | 2008-04-17 | |||
| JP2004115903A | 2004-04-15 |
Foreign References:
| WO2015105186A1 | 2015-07-16 | |||
| WO2015105187A1 | 2015-07-16 |
Attorney, Agent or Firm:
Kenji Yokoi
Yokoi Satoshi
Hiroshi Yokoi
Yokoi Satoshi
Hiroshi Yokoi