PURPOSE: To thermal cracking appratus, using a double structural tube constituted of an outer layer consisting of a specific austenitic heat-resistant steel and an inner coating layer mode of a specific alloy, and further improved tubes in parts where a material to be treated is at the highest temperature.
CONSTITUTION: A thermal cracking apparatus using a double structural tube constituted of (A) an outer layer consisting of austenitic heat-resistant steel consisting of 0.01W0.6wt% C, 0.1W2.5wt% Si, 0.1W2.0wt% Mn, 20W30wt% Cr, 18W40wt% Ni, 0.01W0.15wt% N and the remainder Fe which may be partially substituted by 0.1W5.0wt% range one or more elements selected from Mo, W and Nb and (B) a coating layer, made of an alloy consisting of 0.3W1.5wt% C, 0.1W3.0wt% Si, 6W15wt% Mn, 20W30wt% Cr, 0.1W10wt% Ni, 0W3.0wt% Nb, 0.01W0.15wt% N and the remainder of Fe, coating the inner surface of the above-mentioned outer layer, and having 0.3W5mm thickness as a tube in the downstream part in which the temperature of the flow in the tube is at 700W 950°C.
SHINOHARA TAKAYORI
SUGITANI JUNICHI
TSUCHIDA KOJI
UMEMURA TETSUO
KUBOTA LTD
OSAKA SEKIYU KAGAKU KK
| JPS58198587A | 1983-11-18 |
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