Shear spinning of nickelbased super alloys and stainless steel

Sammanfattning: Shear spinning of Haynes 282, Alloy 718, Alloy 600 and AISI 316L was done using several tool feeds and mandrel clearances. Multi passing of the materials was limited due to strain hardening and circumferential cracking except for AISI 316L. The effect of the tool feed and the mandrel clearance on the successful forming of the materials was established. The successfully spun samples were solution heat treated at varying temperatures and holding times to establish a range of grain sizes and hardness levels. An aging heat treatment process was performed for Haynes 282 and Alloy 718 to achieve precipitation strengthening. The micro hardness measurements were conducted for the materials prior to spinning and after spinning. The same was also done after the various heat treatment processes. Grain size mapping was conducted by the use of lineal intercept methods. Comparison of the results in terms of grain sizes and hardness values was done. The temperature ranges suitable for full recrystallization of the materials after the shear spinning were identified and the effect of the holding times on the grain growth established. Comparison with unspun samples showed that the heat treatment times required to achieve comparative hardness and grain sizes were distinctively different.