Boehler Edelstahl Gmbh & Co Kg

Boehler Edelstahl Gmbh

Gerhard Lichtenegger

Günter Schirninger

Johann Sammer

Reinhold Schneider

Klaus Sammt

Process for manufacturing cylindrical hollow bodies with a circular cross-section using solid rough material of corrosion-resistant, martensitic chromium steels. A remelting block is produced and a tube blank is made therefrom, the tube blank being formed into a tube at hot forming temperature by extrusion at a deformation ratio of at least 6. Hollow bodies are cut from the resultant tube.

Process for manufacturing a cylindrical hollow body and hollow body made thereby

Maraging steel with improved machinability, good weldability, and high corrosion resistance, a process for the heat treatment of such a steel, as well as its use. According to the invention this steel contains (in % by weight) 0.02-0.075% carbon; 0.1-0.6% silicon; 0.5-0.9% manganese; 0.08-0.25% sulfur; maximum 0.04%; phosphorus; 12.4-15.2% chromium; 0.05-1.0% molybdenum; 0.2-1.8% nickel; maximum 0.15% vanadium; 0.1-0.45% copper; maximum 0.03% aluminum; 0.02-0.08% nitrogen; as well as optionally one or more additional alloying elements up to maximum 2.0%, residual iron, and impurities caused in manufacturing, and a ferrite percentage in the structure of less than 28% by volume. A process is also provided for the heat treatment of a maraging steel with improved machinability, which process makes an object that is through-hardened even with a large cross-section, lies essentially in that a steel block with the above composition is subjected in a first step to an annealing treatment for the formation and adjustment of a ferrite percentage in the structure and in a second step a hot forming of the same takes place, after which in a third step a soft annealing and then a thermal tempering are performed.

Growing community of inventors

Kapfenberg, Austria

Gerhard Lichtenegger