The Microstructure Evolution and Control of Alloy 690 during Cold Rolling

The microstructure evolution and control for Alloy 690 during cold rolling and annealing treatment was investigated. Cold rolling specimens were deformed in the strain range from 15% to 70% with strain rates from 0.01 to 10s-1. Subsequent annealing treatment was carried out in the range of 1060~1100°C for dwell time 3~15mins. Rolling reduction, annealing temperature and annealing time except strain rate had obviously influence on grain size and hardness. Little coarsening of grains were observed below 1060°C during annealing treatment, whereas grains coarsened obviously over 1080°C. Besides, the behavior of grain growth for alloy 690 was investigated systematically.