Abstract: The critical points and continuous cooling transformation curves of steel 14CrlMoR (/% ：0. 01C, 0. 66Si,0. 80Mn, 0. 006P, 0. 003S, 1.72Cr, 0.31 Mo, 0. 01 Nb) are measured by dilatometer, and the effect of cooling rate on structure and microhardness of test steel is studied. Results show that with cooling rate 0. 1 ~ 1℃ /s the transformed structure of tested steel is ferrite and pearlite； with 2 ~5℃ /s the tested steel obtains mixed structure of ferrite, pearlite and minor granular bainite； with 10℃/s the structure of test steel is ferrite and granular bainite； with 15 ~20℃/s the structure is lath bainite ；and with 25 ~5℃/s the steel gets the mixed structure of lath bainite and martensite.

摘要： 利用膨胀仪测定了14CrlMoR钢（/%:0.01C,0.66Si,0.80Mn,0.006P,0.003S,1.72Cr,0.31Mo,0.01Nb）的临界点及连续冷却转变曲线并研究了冷却速度对试验钢的组织及显微硬度的影响。结果表明,当冷却速度为0.1~1℃/s时,试验钢的转变组织为铁素体和珠光体;2~5℃/s时,试验钢得到铁素体、珠光体以及少量粒状贝氏体的混合组织;10℃/s时,试验钢组织为铁素体和粒状贝氏体;15~20℃/s时为板条贝氏体组织;25~50℃/s时,该钢得到板条贝氏体和马氏体的混合组织。