Necessity of Post-weld Heat Treatment for Alkaline Solution Transporting Pipeline

Alkaline solution (NaOH) is a medium,which could cause stress corrosion of pipeline steel.The post-weld heat treatment (PWHT) is an effective method to eliminate the residual internal stress and avoid the stress corrosion of the weld seam.There are different stipulations for the necessity of the alkaline solution trasporting pipeline in the same project by different contracts.According to the relevant national standard and specification,the necessity of PWHT is discused for the alkaline solution trasporting pipetine.