THE CLEANING OF 303 STAINLESS STEEL

Shen, T H

Lawrence Livermore National Laboratory

关键词: Nitric Acid;    Stainless Steel-303;    36 Materials Science;    Passivation;    Stainless Steels;   

DOI  :  10.2172/15009833
RP-ID  :  UCRL-TR-203711
RP-ID  :  W-7405-ENG-48
RP-ID  :  15009833

美国|英语

来源: UNT Digital Library

【 摘 要 】

The sulfur found on the surfaces of stainless steel 303 (SS303) after nitric acid passivation originated from the MnS inclusions in the steel. The nitric acid attacked and dissolved these MnS inclusions, and redeposited micron-sized elemental sulfur particles back to the surface. To develop an alternative passivation procedure for SS303, citric and phosphoric acids have been evaluated. The experimental results show neither acid causes a significant amount of sulfur deposit. Thus, these two acids can be used as alternatives to nitric acid passivation for NIF applications. For SS303 previously passivated by nitric acid, NaOH soak can be used as a remedial cleaning process to effectively remove the sulfur deposits.