Strong, seamless a1-alloy flasks - for the conveyance of pressurised gases

摘要

Seamless, strong-walled Al-alloy flasks for the storage and/or transport of pressurised or liquefied gases are based on the well-known Al-Mg-Si alloy. The neck of the cylinder is produced by a multi-stage cold reduction process and heat-treatment is effected in-between the individual drawing stages. An additional heat-treatment phase is conducted for approx. 3 hrs. at 520-550 degrees C at a reducing temp. for the prodn. of the neck section. After being left for half-an-hour there is a 15 hr heat-treatment effected, at a temp. of approx. 160 degrees C. Finally the flask is surface-treated in the usual manner. Ensures good surface quality for the flask and hence prevents the flask from ripping. The superior surface finish removes the necessity for an additional surface-finishing operation to be performed.