One-piece piston with improved combustion bowl rim region and method of manufacture

A piston for an internal combustion engine, comprising:

• a piston body formed as a single, monolithic piece of material having an annular inner wall and an annular outer wall extending concentrically relative with one another along a common central longitudinal axis, said annular outer wall having a wall surface which is parallel to said central longitudinal axis and having a portion in longitudinal overlying axial alignment, with respect to said central longitudinal axis, with an upper wall surface of said annular inner wall, said body having an upper combustion surface with a combustion bowl depending from the upper combustion surface;
• said piston body further including a ring belt region formed in said annular outer wall, said ring belt region being configured for receipt of at least one piston ring adjacent said upper combustion surface;
• said piston body further including a cooling gallery configured in radial alignment with the ring belt region;
• said piston body further including an annular combustion bowl rim region extending between said upper combustion surface and said combustion bowl;
• and
• a bonded seam extending from said combustion bowl rim region radially outwardly to said cooling gallery, said bonded seam having material properties with an enhanced ability to withstand the extreme temperature, pressure, stress and highly corrosive and erosive effects of the combustion gases relative to the surrounding material of said piston body.