Clean-integrity processing and characterization of nuclear-grade austenitic steel components

ABSTRACT

Clean-integrity processing of nuclear-grade AISI 316L austenitic stainless steel components finished by the wire brush and sequent flap discs is performed for high-performance manufacturing of the nuclear power plant equipment. Two steel wire brushes of AISI 304 austenitic stainless steel and 65Mn carbon spring steel are used for the grinding under a spindle speed of 550–2000 rpm. Sequent polishing is carried out by the flap discs using silicon carbide cloth under 2000 rpm. An equivalent pitting corrosion resistance to that of the original stainless steel in 3.5% NaCl solution is obtained for finished samples by the combined processes. The contaminants composition of ground stainless steel samples is determined by the redness degree of chromaticity inspection. The contaminants microstructure and finishing-induced microstructure are dependent on the impedance phase angle change in eddy current impedance diagrams. The surface clean-integrity of nuclear-grade stainless steel is characterized by the series of nondestructive evaluation methods.

KEYWORDS:

• Finishing
• clean-integrity
• steel
• austenite
• surface
• evaluation
• corrosion

Acknowledgments

The authors are grateful for technical assistance from Profs. L. Lin and J. Zhao, and Drs. C. Q. Cheng and B. C. Zheng. This work is supported by the National Basic Research Program of China under Grant No. 2015CB057300, and the Foundation for Innovative Research Groups of the NSFC under Grant No. 51621064.

Disclosure statement

No potential conflict of interest was reported by the author(s).