Compressor housing for turbocharger and method for manufacturing the same

A compressor housing for a turbocharger configured to house a compressor impeller, the compressor housing comprising:

• an intake port configured to suck in air toward the compressor impeller;
• a shroud part having a shroud surface that surrounds the compressor impeller in a circumferential direction;
• a diffuser part that is formed on an outer circumferential side of the compressor impeller in the circumferential direction and is configured to pressurize air discharged from the compressor impeller;
• and
• a scroll chamber configured to guide compressed air having passed through the diffuser part to outside;
• wherein
• the compressor housing is dividably composed of a plurality of pieces including a scroll piece having at least the intake port and a portion of the scroll chamber, and a shroud piece having at least a portion of the scroll chamber, a portion of the diffuser part, and the shroud part,
• the scroll piece and the shroud piece are assembled to each other by press-fitting a press-fitting portion of the shroud piece into a press-fitted portion of the scroll piece in an axial direction, and
• the scroll piece and the shroud piece are sealed to each other by annularly forming a plastic flow portion that is formed by plastic flow caused to a pressure-contacting portion and a pressure-contacted portion by pressure-contacting the pressure-contacting portion that is provided on either one of the scroll piece and the shroud piece with the pressure-contacted portion that is provided on the other one of the scroll piece and the shroud piece in the axial direction, wherein the scroll piece and the shroud piece are made from the same material.