| 摘要 |
PURPOSE: To simplify the assembly work with a reduce number of parts and absorb the difference of expansion degrees of a cylindrical body and a porous sheet due to thermal expansion in order to prevent separation of a catalyst by making an inner cylinder of an exhaust gas purifying apparatus up of a stainless steel having a higher coefficient of linear thermal expansion than that of a specified ferritic stainless steel sheet. CONSTITUTION: One end part 22a of an inner pipe 22 is inserted in one end part 21a of a cylindrical body 21 and welded for temporary fixation and the whole circumferential parts of one end parts 21a, 22a are fixed in the other end parts 11b of a first exhaust gas discharging pipe 11. Moreover, the other end part 22b of the inner pipe 22 is inserted in one end part 13a of a second exhaust gas discharging pipe 13 and the whole circumferential parts of the other end parts 21b, 14b are fixed in one end part 13a. A porous sheet of which the inner pipe 22 is composed is a ferritic stainless steel sheet containing Cr 16-18%, C not more than 0.12%, Mn not more than 1, and Si not more than 0.75. On the other hand, the cylindrical body 21 is made of a stainless steel sheet having higher coefficient of linear thermal expansion than that of the inner pipe 22. |
