Abstract: Systematic experimental research is made,involving the influence by the manufacturing process on the performance of the X70 grade elbow.Different heat treatment processes are used as trials to treat the stock of the elbow,based on which together with the inspection results of the products by the trial productions,a rather applicable manufacturing process for the said elbow is built up,covering such tips as bending temperature range of 900~1 050 ℃,heating bandwidth of 40~80 mm,cooling type of one-side forced water cooling and temper temperature range of 450~550 ℃.The newly-built manufacturing process for the X70 elbow is proved applicable and practical on the basis of the inspection results of individual pieces of the Ф1 060 mm×17.5 mm,Ф1 060 mm×21 mm,Ф1 060 mm×26.2 mm elbows processed with the trunk line pipes,the trial-manufactured small lots of the elbow as well as 50 pieces of the Ф1 060 mm×21 mm elbow from the first trial massive production.