Details

Autor(en) / Beteiligte

• FU, Haiying
• NAGASAKA, Takuya
• MUROGA, Takeo
• KIMURA, Akihiko
• UKAI, Shigeharu

Titel

Effect of HIP Temperature and Cooling Rate on Microstructure and Hardness of Joints for ODS-RAFM Steels and JLF-1 Steel

Ist Teil von

• Plasma and Fusion Research, 2016/04/15, Vol.11, pp.2405039-2405039

Ort / Verlag

Nagoya: The Japan Society of Plasma Science and Nuclear Fusion Research

Erscheinungsjahr

2016

Link zum Volltext

Quelle

Electronic Journals Library

Beschreibungen/Notizen

• Dissimilar-metal joints between ODS-RAFM (oxide-dispersion-strengthened reduced activation ferritic/martensitic) steels and JLF-1 steel were fabricated by hot isostatic pressing (HIP) at 1000 - 1100 ◦C with a cooling rate of 5 ◦C/min. After the HIP, it was always quenched martensite for JLF-1 steel. However, coarse precipitates were found in 9Cr-ODS. Additional annealing experiments to simulate HIP conditions were conducted for 9Cr-ODS with cooling rate ranged from 0.5 to 36 ◦C/min at 800 - 1100◦C. The results showed that, to form quenched martensite for 9Cr-ODS, the HIP temperature should be above 1000 ◦C with cooling rate no less than 25 ◦C/min. When the cooling rate is increased to 36 ◦C/min, the microstructure of 9Cr-ODS is quenched martensite with precipitate size similar as that before HIP. If the limitation of precipitate size in 9Cr-ODS is 0.2 µm, HIP temperature above 1050 ◦C with cooling rate no less than 30 ◦C/min is needed. In this case, post-weld heat treatment (PWHT) with only tempering is necessary to recover the microstructure of 9Cr-ODS to tempered martensite. For 12Cr-ODS, the HIP temperature and cooling rate has no effect on hardness and precipitate size. PWHT is not necessary for the single-metal joint of 12Cr-ODS from the view point of precipitation control. However, for the dissimilar-metal joints between ODS-RAFM steels and JLF-1 steel, the PWHT condition should be comprehensively determined by considering microstructural evolution of each part in the joints after HIP.