10.9级耐候钢XG835NH奥氏体连续冷却转变行为

Continuous cooling transformation behavior of austenite of 10.9 grade XG835NH weathering steel

利用热模拟试验机对XG835NH钢的奥氏体连续冷却动态转变曲线进行了测定和分析。结果表明:冷却速度在0.5℃/s以下,组织为铁素体+珠光体;当冷却速度超过0.5℃/s,小于1℃/s时,组织为铁素体+珠光体+贝氏体混合组织;当冷却速度超过1℃/s时,出现少量马氏体组织;当冷速超过5℃/s时,组织主要为马氏体。实际生产时,通过控制冷却速度,可获得适合拉拔和冷镦的XG835NH钢盘条。

Continuous cooling transformation curves of XG835NH steel were determined and analyzed by using thermal simulation testing machine. The results show that the microstructure of the steel is composed of ferrite and pearlite when the cooling rate is below 0.5 ℃/s. When the cooling rate is between 0.5 ℃/s and 1℃/s, the microstnacture is composed of ferrite, pearlite and bainite; when the cooling rate is higher than 1 ℃/s, a small amount of martensite can be observed; when the cooling rate exceeds 5 ℃/s, the microstructure is mainly composed of martensite. In actual production, the XG835NH steel wire rod suitable for drawing and cold heading can be obtained by controlling the c, ooling rate.