为研究DP1180汽车用双相钢连续冷却转变过程中的相变特性，对不同冷却速率下的DP1180双相钢试样进行了金相检验及显微硬度测试，绘制了该双相钢的连续冷却转变曲线，并分析了DP1180钢在连续冷却过程中的相变规律。结果表明：对于DP1180汽车用双相钢，其连续冷却转变曲线分为铁素体转变区、贝氏体转变区和马氏体转变区。当冷却速率小于0.5℃·s^-1时，主要发生铁素体-贝氏体转变；当冷却速率增大到1℃·s^-1时，显微组织中出现马氏体；随冷却速率逐渐增大，铁素体不断减少，当冷却速率达到10℃·s^-1时，组织变为马氏体+贝氏体；当冷却速率大于40℃·s^-1时，组织主要为马氏体。

In order to study the phase transformation characteristics of DP1180 dual phase steel for automobile during continuous cooling transformation, metallographic examination and microhardness test were carried out on DP1180 dual phase steel samples under different cooling rates. The continuous cooling transformation curve of the dual phase steel was drawn, and the phase transformation law of DP1180 steel during continuous cooling was analyzed. The results show that the continuous cooling transformation curve of DP1180 dual phase steel for automobile is divided into ferrite transformation zone, bainite transformation zone and martensite transformation zone. Ferrite-bainite transformation mainly occurs when the cooling rate is less than 0. 5 ℃·s^-1. The martensite appears in the microstructure when the cooling rate increases to 1 ℃·s^-1. The ferrite decreases with the increase of cooling rate, and the microstructure becomes martensite and bainite when the cooling rate reaches 10 ℃·s^-1. The microstructure is mainly martensite when the cooling rate is higher than 40 ℃·s^-1.