The Effect of Grain Size on the Susceptibility towards Strain Age Cracking of Wrought Haynes® 282®

Abstract

The effect of grain size on the suceptibility towards strain age cracking (SAC) has been investigated for Haynes 282 in the tempeature range of 750 to 950C after isothermal exposure up to 1800s. Grain growth was induced by heat treating the material at 1150C for 2h, resulting in a fourfold increase in grain size. Hardness was significanlty reduced after heat treatment as compared to mill-Annealed material. Large grain size resulted in intergranular fracture over a wider temperature range than small grain size material. Ductility was lowest at 850C, while lower values were observed to be correlated to increased grain size. The rapid formation of grain boundary carbide networks in Haynes 282 is found to be not able to compensate for higher local stresses on grain boundaries due to incresed grain size.