| 摘要 |
The present invention relates to a cylinder tube (10) for scraped surface heat exchangers the interior surface (18) of which is even and the exterior surface of which is enclarged by providing a number of spaced grooves (16) with a smoothly rounded bottom portion, the profile depth (A) of which being substantially larger than the radius (R) at the bottom of said groove (16). The cylinder tube (10) shall be manufactured by a duplex stainless steel alloy consisting of the following constituents in weight-%; max 0.03 % C, 18-30 % Cr, 4-8 % Ni, 0-6 % Mo, 0.5-2% Mn, 0.5-2 % Si, 0.05-0.30 % N, the remainder Fe and normal impurities, whereby the amounts of the constituents are interrelated such that the amount of ferrite in the microstructure amounts to 35-65 %. |
