摘要 |
The invention provides a tube for use in furnaces where gas and liquid media are being passed through the tube from one end to the other while being subjected to substantial heating and decomposition resulting therefrom. The tube is made of a stainless iron-nickel-chromium-base alloy comprising in weight-% max 0.08% C, 23-27% Cr, 33-37% Ni, 1.3-1.8% Mn, 1.2-2% Si, 0.08-0.25% N, 0.01-0.15% rare earth metals, and Fe and usual impurities. The cylindrical tube has a smooth outer surface and an inner surface provided with valleys or recesses extending longitudinally with a smoothly curved bottom profile.
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