Patent ID: 7156979
Filing Date: 2007-01-02
Classification: C21D,C22C,C23C,F28F,Y10T

Abstract:
1. A process for the thermal cracking of a hydrocarbon comprising passing said hydrocarbon at elevated temperatures through stainless steel tubes, pipes, or coils having an inner surface, said inner surface having an outermost surface covering not less than 60% of stainless steel comprising from 20 to 50 weight % of Ni, from 13 to 50 weight % of Cr, 0.2 to 3.0 weight % Mn, from 0.3 to 2.0 weight % of Si and less than 5 weight % of titanium, niobium and all other trace metals, and carbon in an amount less than 0.75 weight %, said surface having a resistance to coke formation when the stainless steel is exposed to a hydrocarbon environment at high temperatures and having a thickness from 0.1 to 10 microns and substantially comprising a spinel of the formula MnCr 2 O 4 .