Piston used for combustion engines, has piston lower portion with piston shell, which is made of ultrahigh-carbon-containing lightweight construction steel, and piston upper portion with piston head, which is made of steel

摘要

A piston has piston lower portion with piston shell and piston upper portion with piston head. The piston lower portion made of ultrahigh-carbon-containing lightweight construction steel. The piston upper portion made of steel. Independent claims are included for the following: (1) semi-finished material of lower portion of piston; (2) semi-finished material of upper portion of piston; and (3) manufacture of piston.