Effect of Deformation of Metastable Austenite on Secondary Hardening and Corrosion Resistance of 13% Cr Stainless Steel

Yuzo Hosoi
1963 Tetsu-to-Hagané Overseas  
Synopsis T he secondary hardening characteristics and the corrosion resistance of 13"10 Cr stainless steels, which /L'ere diformed in the metastable austenite condition /Jrior to oil quenching, /L-ere investigated. I n tem/Jerillg, the secondary hardening occurred at about 450°C and began to disa/Jpea r when the amount of diformation in the metastable austenite was increased. By measuring the change in ha/f-l'alue breadth oj X-ray diffrac tion lines with tem/lering, and extracting carbides
more » ... cting carbides electrolj,tically from the heat treated steel, it was determined that the secondary hardening and the corrosion resistance were related to the acceleration qf carbide /Jreci/litation and the increase in the lattice strain induced by /llastic deformation qf the austenite matrix /Jrior to oil quenching . A cause of the secondmy hardening was also suggested and discussed. .J Oo~ boiling H NO" aqueous solution and 5% H 2 SO" aqueous solution at room tem/lerature were em/Jloyed as the corrosil'e media for the corrosion tests. T he corrosion resistance is not influenced by allstenite difonnation at .J50°C when the steel has beel! austelliti:::ed at 950o~ 1000°C. H owever, the corrosion resistance is decreased by austenite diformation at 650°C, especially in 5~o H 2 SO". It seemed tltat this poorer corrosion resistance by diformation at 650°C was due to a heterogeneity of the structure induced by tlte /noduct of isothermal trallifonnatiolJ that was accelerated by the diformation .
doi:10.2355/isijintoverseas.3.1_42 fatcat:c76cap56czaoffj3hmztmpladi