For 16MM thick 16MNDR material with a medium of hydrochloric acid and calcium chloride, is weld post-heat treatment required for the equipment?
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This post was last edited by Desert Fish on 2021-12-19 at 18:18. Dear colleagues, for a 16MM thick 16MNDR material exposed to hydrochloric acid and calcium chloride, is weld heat treatment necessary?
The main purpose of post-weld heat treatment is to improve the corrosion resistance and cold crack resistance of the workpiece.
Can 16MNDR resist hydrochloric acid corrosion?
It’s not hydrochloric acid; the medium is gaseous hydrogen chloride
Hydrogen chloride is classified as highly hazardous in HG/T20660-2017. According to this rule, heat treatment is required.
What does the poster mean by “the medium is hydrochloric acid and calcium chloride”? Is it a heat exchanger or a jacketed vessel, with dry hydrogen chloride gas on one side and calcium chloride solution serving as the cooling medium on the other side? If so, the main focus should be on the moisture content in the dry hydrogen chloride gas, in order to prevent the formation of free acid mist during cooling or in winter conditions, which could cause corrosion and damage to the equipment.
Page 100 of TSG21-2016 clearly states that the medium properties shall be determined in accordance with HG20660-2000.
Find a reason that meets the heat treatment requirements in accordance with clause 8.2 of 150.4-2011. If the container is free from stress corrosion and the customer does not require heat treatment, then there is no need for heat treatment.
I’ve learned that polyaniline has good corrosion resistance; I’ll give it a try if I get the chance