Method for the production of a piston for an internal combustion engine

Method for the production of a piston (1) for an internal combustion engine, having the following method steps:

• production of an upper piston part (3, 3′, 3″) made of tempered steel, using the forging method, which has a piston crown (6) having a combustion bowl (7, 7′), a ring wall (8) formed onto the piston crown radially on the outside, directed downward, and a ring-shaped support (10) disposed radially within the ring wall (8) formed onto the underside of the piston crown (6), whereby the upper part of a cooling channel (22) is formed between the ring wall (8) and the support (10),
• production of a lower piston part (4) made of steel, using the forging or casting method, which has two skirt elements (11, 12) that lie opposite one another, which are connected with one another by way of two pin bosses (13, 14) that lie opposite one another, a ring-shaped contact part (17) disposed on the top of the lower piston part (4) and connected with the pin boss (13, 14), and a circumferential ring rib (18) disposed radially outside of the contact part (17) and connected with the skirt elements (11, 12), whereby the lower part of the cooling channel (22) is formed between the contact part (17) and the ring rib (18),
• welding of the upper piston part (3, 3′, 3″) to the lower piston part (4) by way of contact surfaces that enter into contact with one another, of the ring wall (8) and the ring rib (18), on the one hand, and of the support (10) and the contact part (17), on the other hand, whereby the cooling channel (22) formed by the upper piston part (3) and by the lower piston part (4) is closed,
• finishing of the piston (1) using a chip-cutting production method,
• wherein
• for production of the upper piston part (3, 3′, 3″), an upper piston part blank is forged using the semi-hot-forming method, at 600° C. to 900° C., after which the combustion bowl (7, 7′) and/or the upper part of the cooling channel (22) undergo no further processing, and after which the radially outer region (23) of the piston crown (6), the radially outer region of the ring wall (8), the lower region (26) of the inner surface (27) of the ring wall (8), and the contact surface (28) of the support of the upper piston blank are finished to produce the upper piston part (3, 3′, 3″).