Two tubes of 250 maraging steel, one forward shear-spun and the other backward-spun, were studied both in the cold-worked state and after two different heat treatments: i) solution treatment followed by aging; ii) aging directly after cold working. X-ray measurements of preferred orientation and the calculation of the Crystallite urientation Distribution Function (CODF) were used as input for computation of Young's Modulus and the yield-stress anisotropy of the tubes. The predicted anisotropy of Young's Modulus in the tube wall was low but plastic properties were predicted to show higher anisotropy. After cold working, as well as after subsequent aging, higher uniaxial yield values are predicted for loading in the axial tube direction than in the tangential direction. Solution treatment between cold working and aging is predicted to change the yield behaviour, which is expected to become nearly isotropic. In all cases the through-thickness yield-stress is predicted to be lower than either the axial or the tangential yield-stress.

P. Ari-Gur

Papers

Anisotropy of 250 maraging steel shear-spun tubes.