CAJ | 학술논문

采用Gleeble-1500热模拟试验机并结合微观组织和力学性能测试,分析了不同铌、钼含量对管线钢的组织、力学性能和CCT曲线的影响.结果表明:随钼的质量分数增加,针状铁索体的含量增加,并且出现了M-A组织.铌在钢中可抑制奥氏体的再结晶,保持变形效果从而细化铁素体晶粒,得到细小的贝氏体组织,并且铌含量的增加使得管线钢强度和硬度鄙相应增大,冲击韧度降低.在连续冷却转变过程中,钼元素的加入使相变点温度降低,在相同的冷却条件下容易发生贝氏体转变,并使其CCT曲线向右移.而铌元素的加入增大了过冷奥氏体的稳定性,相变点温度降低,并且推迟珠光体的转变.
채용Gleeble-1500열모의시험궤병결합미관조직화역학성능측시,분석료불동니、목함량대관선강적조직、역학성능화CCT곡선적영향.결과표명:수목적질량분수증가,침상철색체적함량증가,병차출현료M-A조직.니재강중가억제오씨체적재결정,보지변형효과종이세화철소체정립,득도세소적패씨체조직,병차니함량적증가사득관선강강도화경도비상응증대,충격인도강저.재련속냉각전변과정중,목원소적가입사상변점온도강저,재상동적냉각조건하용역발생패씨체전변,병사기CCT곡선향우이.이니원소적가입증대료과랭오씨체적은정성,상변점온도강저,병차추지주광체적전변.
Through Gleeble-1500 thermal mechanical simulation and microstructure and mechanical properties test,the effects of Mo and N-b content on microstructure,mechanical properties and CCT curves of the pipeline steel were analyzed.The results show that,with the increase of Mo content,the acicular ferrite's content increases,and M-A microstructure appears.Nb may suppress austenite recrystallization in the steel,maintains the distortion effect and fines ferrite grain,which can obtain the tiny bainite microstructure.With the increase of Nb content,the strength and hardness of the pipeline steel increase,but the impact toughness decreases.In the continuous cooling transformation,Mo adding reduces the temperature of phase transformation point,makes the bainite transformation easier under the same cooling condition,and causes CCT curves to move toward right.But Nb adding increases the under-heating austenite stability,reduces the temperature of phase transformation point and postpones the transformation of pearlite.