公开(公告)号：US20200340388A1

公开(公告)日：2020-10-29

申请号：US16857245

申请日：2020-04-24

Applicant: KUBOTA Corporation

Inventor： Hiroki OSO ,  Nobuyoshi OKADA ,  Hideyuki KOYAMA ,  Yoshinori TANAKA ,  Kenji OKAMOTO

IPC: F01N13/16 ,  F01N13/18 ,  F01N13/10 ,  F02B37/02

Abstract: Provided is an exhaust system for an engine in which a fastening force of a fastener hardly decreases. An exhaust system for an engine includes: an exhaust passage component of ferrous metal; and a fastener that fastens the exhaust passage component to other parts, the exhaust passage component including a pressure receiving surface that receives a fastening force of the fastener. The oxide film of triiron tetraoxide is formed on the pressure receiving surface of the exhaust passage component. It is preferable that the oxide film of triiron tetraoxide be also formed on an outer surface other than the pressure receiving surface of the exhaust passage component. It is preferable that the oxide film of triiron tetraoxide be also formed on an inner surface of the exhaust passage component.