Mannesmann Aktiengesellschaft

Dieter Vespermann

Ingo Von Hagen

Ernst W Lange

Bernhard Hoffmann

Karl Scholl

Heinz Muller

A process for the manufacture of a seamless pressure vessel and the seamless pressure vessel produced thereby, the process including the steps of employing an aluminum-killed CrMo steel which includes by wt. %: 0.28-0.39% C; 0.15-0.40% Si; 0.45-0.90% Mn; max. 0.02% P; max. 0.005% S; 0.90-1.30% Cr; 0.15-0.35% Mo; 0.0010-0.040% Ti; 0.001-0.003% B; and 0.003-0.010% N; hot working the alumninum-killed CrMo Steel to produce the seamless pressure vessel, austenizing the seamless pressure vessel at a temperature between about 830.degree. C. and about 880.degree. C.; cooling the seamless pressure vessel at a cooling rate of between about 5.degree. K/s and about 15.degree. K/s; and tempering the seamless pressure vessel at a temperature between about 510.degree. C. and about 660.degree. C.

Process for the manufacture of seamless pressure vessels and its named

A pressure vessel for the storage of gas has a bottom part, a cylindrical jacket and a head part with a neck, these parts are made of a corrosionproof stainless steel having up to 0.06% C, from 1.5 to 6% Mn, from 0.3 to 1% Si, from 16 to 25% Cr, from 4 to 18% Ni, from 0 to 4% Mb, from 0 to 0.35% nitrogen, from 0 to 0.25% Nb, all percentages by weight, the remainder being iron with the conventional low level impurities; following shaping, the interior surfaces are electrochemically polished; a valve with an adapter is provided for adapting dimensions of the valve to the neck, and a protective cap is threaded onto an upper portion of the head part; through welding or a non welded e.g. a threaded connection the adaptor is connected to the valve, and a nut or welding connection connects the adaptor to the neck.

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Moers-Kapellen, Germany

Dieter Vespermann