摘要
为明确相变效应对X65管线厚板控制冷却的影响,通过开发线性混合热膨胀模型、拓展Avrami相变动力学模型和应用Leblond模型建立了热力耦合有限元模型.用该模型研究了X65管线厚板在上下层流冷却系数分别为3和1 kW/(m2.K)的非对称控制冷却时,相变效应对温度、残余应力和应变的影响.结果表明:相变期间,潜热减缓心部和下表面的冷却速度达50%、25%;潜热和TRIP效应分别产生峰值为89、-89 MPa,并且130、-170 MPa的应力可减小整体残余应力;相变膨胀产生峰值为723、-479 MPa的组织应力决定了整体残余应力大小及分布.
To study the phase transformation effect during the controlled cooling of X65 heavy pipeline plate,a thermomechanical coupled finite element model was established,where the developed linear mixture thermal expansion model,the modified Avrami transformation dynamics model,and the Leblond model were combined.Using the model,the influence of transformation effect on temperature,residual stress,and strain was studied during the asymmetric controlled cooling of X65 heavy pipeline plates with 3 kW/（m2·K） laminar cooling coefficient on top surface and 1 kW/（m2·K） on bottom surface.The result shows that latent heat slowed the cooling speed of inner and bottom surface by 50%and 25%,respectively,during the phase transformation.Peak stresses,89 MPa and-89 MPa,were induced due to latent heat,and 130 MPa and-170 MPa from TRIP（transformation induced plasticity） effect.Because of the coexistence of tensile and compressive stresses caused by latent heat and TRIP effect,the overall residual stresses were reduced.Moreover,the magnitude and distribution of the overall residual stresses were dependent significantly on the structural stress with peak values of 723 MPa and-479 MPa from transformation dilatation.
出处
《西南交通大学学报》
EI
CSCD
北大核心
2012年第2期245-251,共7页
Journal of Southwest Jiaotong University
基金
奥地利sterreichischer Akademischer Austauschdienst项目(ACM-2008-00147)
关键词
管线
冷却
热力耦合
有限元
相变潜热
相变膨胀
相变诱导塑性
pipeline
cooling
thermomechanical coupling
finite element
latent heat
transformation dilatation
transformation induced plasticity（TRIP）
