On Formability of MoNiCr Alloy
The paper deals with recrystallization conditions monitoring for MoNiCr nickel superalloy. The alloy is determined for modern concepts of nuclear reactors in which molten fluoride salts are used in the primary and/or secondary circuit as coolants. It represents a material with high corrosion resistance against fluoride salts and it has very good creep properties in the temperature range of interest for such a kind of reactors between 650 – 800 °C as well. The manufacture of vessels and fittings from MoNiCr alloy requires appropriate forming technology for this high-alloyed material. The key moment seems to be forming of the material cast state to the state of cast recrystallized microstructure with a homogenous fine grains. A kind of stress condition is besides temperature very important in the course of a hot forming of this type of hardly deformable materials. Forming with prevailing pressure state of stress increases probability that material can attain level of deformation allowing recovery and recrystallization processes without the material failure. Preceding cold deformation can essentially accelerate the recrystallization process. Investigation of forming condition influence on MoNiCr microstructure and thus its formability is performed here.
Pengcheng Wang, Liqun Ai, Yungang Li, Xiaoming Sang and Jinglong Bu
Z. Novy et al., "On Formability of MoNiCr Alloy", Advanced Materials Research, Vols. 295-297, pp. 1731-1737, 2011