US 11,692,248 B2
Sliding member
Noriaki Chida, Saitama (JP); and Shota Seki, Saitama (JP)
Assigned to NIPPON PISTON RING CO., LTD., Saitama (JP)
Appl. No. 16/768,371
Filed by NIPPON PISTON RING CO., LTD., Saitama (JP)
PCT Filed Nov. 28, 2018, PCT No. PCT/JP2018/043853
§ 371(c)(1), (2) Date May 29, 2020,
PCT Pub. No. WO2019/107442, PCT Pub. Date Jun. 6, 2019.
Claims priority of application No. 2017-230550 (JP), filed on Nov. 30, 2017.
Prior Publication US 2020/0299812 A1, Sep. 24, 2020
Int. Cl. B21D 39/00 (2006.01); C22C 27/06 (2006.01); C23C 14/02 (2006.01); C23C 14/06 (2006.01); C23C 28/02 (2006.01); F16J 9/26 (2006.01)
CPC C22C 27/06 (2013.01) [C23C 14/024 (2013.01); C23C 14/0641 (2013.01); C23C 28/021 (2013.01); F16J 9/26 (2013.01)] 8 Claims
OG exemplary drawing
 
1. A sliding member comprising:
a sliding surface coated with a Cr—B—Ti—V—(Mn, Mo)—N-based alloy film containing one or both of Mn and Mo and having a total content of the Mn and the Mo within a range of 0.1-2 mass %,
a B content is within a range of 0.1 mass % to 1.5 mass %, inclusive, a V content is within a range of 0.05 mass % to 1 mass %, inclusive, and a Ti content is within a range of 0.05 mass % to 1.5 mass %, inclusive, and
an N content is within a range of 30 mass % to 40 mass %, inclusive, and a remnant includes Cr and inevitable impurities; wherein
a toughness evaluation value of a Cr—N alloy coating without B—Ti—V—(Mn,Mo) is 1;
the toughness evaluation value of said Cr—B—Ti—V—(Mn,Mo)—N alloy coating is 1.41 to 1.59,
the toughness evaluation value is the value obtained by multiplying a hardness ratio by a scratch ratio, wherein the hardness ratio is expressed as a relative value of the Vickers hardness value of the Cr—B—Ti—V—(Mn,Mo)—N alloy coating when the Vickers hardness of the Cr—N alloy coating without B—Ti—V—(Mn,Mo) is 1, and the scratch ratio is expressed as a relative value of the scratch ratio of the Cr—B—Ti—V—(Mn,Mo)—N alloy coating when the scratch ratio of the Cr—N alloy coating without B—Ti—V—(Mn,Mo) is 1,
said Vickers hardness is measured by a Vickers hardness tester in accordance with the standards JIS B 7725, ISO 6507 HV(0.05), and
the scratch ratio is measured using a scratch test device to determine a limit load at which peeling of the alloy film occurs when a force is applied parallel to the alloy film on a table at a table speed of 10 mm/min, and
the scratch test device comprises an indenter having a load loading speed of 100 N/min, indenter tip R of 0.2 mm, and test load of 0 to 100N; the alloy film is pressed against a test specimen of SKH51; and the scratch ratio is determined from a scratch load measured by an AE (acoustic emission) generation detected by an AE detector with a sensitivity of 1.2 when the test specimen is moved a distance of 5 m.