ISSN:
1662-9752
Source:
Scientific.Net: Materials Science & Technology / Trans Tech Publications Archiv 1984-2008
Topics:
Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
Notes:
The effects of nickel content and heat treatment conditions on the creep strength ofprecipitation-strengthened 15Cr ferritic steel were investigated. The creep strength of the 15Cr ferriticsteel was drastically improved by solution treatment and water quenching. However, over the longterm, the detrimental effect of nickel on the creep strength was pronounced for water-quenched steels.The volume fraction of martensite phase increased with increased nickel content in both thefurnace-cooled and water-quenched steels. The volume fraction of martensite phase in thewater-quenched steel was smaller than that in the furnace-cooled type, even for the same nickelcontent. Fine particles, smaller than 500 nm, were precipitated homogeneously within the ferritephase of the water-quenched steel. On the other hand, coarse block-like particles 1 $m in size wereprecipitated sparsely within the martensite phase. The creep strength of the steels decreased withincreased volume fraction of the martensite phase caused by furnace cooling and nickel addition. Thelower creep strength and microstructural stability of the martensite phase is attributable to lessprecipitation strengthening. To enable this steel to be put to practical use, it will be necessary tosuppress the formation of the martensite phase caused by addition of nickel by optimizing thechemical composition and heat treatment conditions
Type of Medium:
Electronic Resource
URL:
http://www.tib-hannover.de/fulltexts/2011/0528/02/15/transtech_doi~10.4028%252Fwww.scientific.net%252FMSF.539-543.2994.pdf
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