Hydrogen-induced cracking of a stainless-steel dryer support component in a petrochemical plant

摘要

VINYL-CHLORIDE monomer and poly-vinyl chloride are extensively used as raw materials V by the plastic industry. Petrochemical plants that produce these raw materials are often highly structured units employing a wide variety of engineering materials in their construction and design. The selection of a particular material is based on the performance of a component required under specific conditions. This paper describes the materials' evaluation of a dryer support component used in the drying unit of a PVC plant. 'The component was made of 304-type stainless steel and was fractured after a relatively-short period of service. Various techniques used for materials analysis included scanning-electron microscopy combined with energy dispersive X-ray spectroscopy and diffraction. The dryer support appeared to fail by hydrogen-induced cracking (MIC). Based upon the results obtained, It was recommended to use an alloy more resistant to hydrogen induced cracking such as the 309-type stainless steel.