超级铁素体钢S44660脆性现象探讨

Study on Brittleness of Super Ferritic Stainless Steel S44660

由于S44660方坯在轧制后堆冷至室温后发现部分脆断,紧急采用高温固溶也脆断,检验表明轧后有原始晶粒度、高温固溶晶粒度较粗大,晶界断裂,稳定化元素Ti高等,为此在50kg感应炉试验,采用Ti+Nb稳定化元素、降低加热及终锻温度、快冷等措施消除了脆性,细化了晶粒,提高了韧性.

There exists brittle fracture in some of $44660 square billets which are stack cooled to room temper- ature subsequent to be rolled, this problem is not solved yet by hightemperature solid solution treatment urgently. The inspection indicates that there exist some problems such as coarse original grain size and high temperature solid solution grain size, fracture grain boundary, higher stabilized element Ti, and so on in the steel after being rolled. In order to solve the problem, the test is conducted in 50kg induction furnace. By using measures of adding Ti＋Nb sta- bilized elements, decreasing heating temperature and finish forging temperature, and fast cooling, the brittleness of the steel is eliminated, the grain in the steel is refined, and toughness of the steel is improved.