Prodn. of brass pipes - by cold working a tubular blank and then annealing in a protective atmos.

摘要

Brass pipes are made by cold-working tubular blanks to a deformation of 75-90% and then annealing at 400-480 deg.C in a protective atmos. The cold-working operation pref. involves cold-rolling or drawing on a pipe mandrel. After the annealing stage, the pipe may then be further drawn with a deformation of 38-48% for the first pass and 3-6% for subsequent passes. A suitable protective atmos. for the annealing stage comprises the combustion prods. of the lubricant on the tube clank. Prods. are used in heat exchangers, marine, chemical and food engineering and in electronics, etc. Accurately dimensioned pipes are obtd. with better productivity than prior methods.