Characterisation of microstructure and its effect on the strength and toughness of 17-4PH stainless steel. (21st September 2009)

• Record Type: Journal Article
• Authors: Das, C.R.; Bhaduri, A.K.; Albert, S.K.; Dasgupta, A.
• Is Part Of: International journal of nuclear energy, science and technology. Volume 4:Number 4(2009)
• Page Start: 355
• Page End: 365
• Publication Date: 2009-09-21
• Subjects: 17-4PH stainless steel -- steel microstructure -- strength -- toughness -- hardness -- long-term ageing; Nuclear energy -- Periodicals; 621.4805
• Languages: English
• ISSNs: 1741-6361

Abstract

The influence of microstructure on the strength and toughness of 17-4 Precipitation-Hardened (PH) Stainless Steel (SS) was studied as a function of duration of ageing at 783 K. Lath martensite is formed in this steel in its solution-annealed condition. X-ray diffraction studies detected the formation of a copper-rich phase after ageing for 0.25 h, with the amount of the copper-rich precipitates increasing with the duration of ageing. The coarsening of the copper-rich precipitates on ageing for 2 h led to a sharp decrease in hardness, which was attributable to the transformation of the coherent copper-rich body centred cubic (b.c.c.) phase to the incoherent copper rich face centred cubic (f.c.c.) phase. Further ageing for 4 h led to a dip in hardness and strength and an increase in toughness. The dip in hardness upon long-term ageing could be attributed to the formation of coarse copper-rich precipitates, which also led to an improvement in the toughness of the material.