摘要
研究了硼对低碳钢晶粒尺寸的影响，结果表明：低碳钢中酸溶硼（[B]s）的质量分数大于0．005％时，随酸溶硼的质量分数增加，铁素体晶粒尺寸明显变大。主要原因为硼的加入使钢的奥氏体晶粒增大，从而使铁素体晶粒尺寸变大；硼的加入抑制铁素体形核并降低相变开始的实际温度，孕育期变长，从而使铁素体晶粒尺寸变大。冷却速度为0．5～5℃／s，随冷却速度加快，晶粒尺寸明显减小；冷却速度为5～15℃／s，晶粒尺寸的变化不大。冷却速度大于5℃／s时，含硼低碳钢明显出现贝氏体，因此热轧后盘条的冷却速度最好控制在5℃／s以下。
Effect of B on grain size of low-carbon steel was investigated in laboratory. The results show that grain size of ferrite becomes bigger with increase of [B]s when [B]s is above 0. 005%. The main reasons are： grain size of austenite increases with [B]s, so grain size of ferrite is increased too; B restrains formation of ferrite nucleus. And B reduces actual temperature of ferrite transformation from austenite, then the incubation period becomes longer. In a cooling rate range of 0.5～5 ℃/s, the grain size of ferrite becomes smaller obviously with increase of cooling rate. When the cooling rate is over 5 ℃/s, the grain size of ferrite does not decrease and bainite in steel containing B can be seen obviously. Therefore, cooling rate of wire rod after rolling of low-carbon steel with B should be lower than 5 ℃/s.
出处
《钢铁》
CAS
CSCD
北大核心
2006年第3期67-70,共4页
Iron and Steel
关键词
低碳钢
硼
晶粒尺寸
low-carbon steel
boron
grain size
