Patent ID: 7685710

Claim:
A method for producing a piston for an internal combustion engine, the piston having an essentially cylindrical base body made of aluminum, whose one face forms a piston crown, pin bosses with pin bores disposed on an underside of the base body facing away from the piston crown, and skirt elements that connect the pin bosses with one another, the method comprising the following steps: producing the base body via forging, so that a recess having a rectangular cross section is formed into a radially outer region of the piston crown; welding free shanks of an essentially toroid-shaped cooling channel, which is C-shaped in cross-section and radially open to the outside, and produced from sheet steel, onto a cylindrical surface of a ring insert made of NiResist, which surface lies radially on an inside, casting the ring insert provided with the cooling channel into a ring element made of aluminum, using a composite casting method, said ring element having a rectangular cross section such that the ring element fits into the recess; fitting the ring element containing the ring insert with the cooling channel into the recess and welding the ring element to the base body; and forming the piston into a final shape by means of a cutting production method.