Ti-Mo析出强化铁素体钢的热变形行为研究

通过利用Gleeble2000热模拟实验机,研究了Ti-Mo系析出强化铁素体钢在应变速率分别为0.1 s^-1,1 s^-1,10 s^-1时的热变形行为。基于热压缩实验数据,分析了流变应力曲线,并结合实验数据回归和理论分析,构建了Ti-Mo钢热变形过程中的流变应力模型。经过验证,模型在不同温度及应变速率下的峰值应力预测值与实验值吻合度较好,平均相对误差分别为3.69%和4.45%。

Effect of Ti-Mo-V composite addition on microstructure andmechanical properties of marine 10Ni5CrMoV steel

The effects of Ti-Mo-V composite addition on the evolution of precipitates in marine 10Ni5CrMoV steel andthe corresponding strength and toughness mechanisms were systematically investigated.Ti-Mo-V composite addition canform the Ti_(x)Mo_(y)V_(z)C carbide with TiC as core and Mo-V as shell in the order of Ti(C)→V→Mo.The yield strength of thespecimens is increased from 815 MPa to 876 MPa due to the nanoscale precipitates enhancing the pinning effect on grainboundaries and dislocations,and the contribution of precipitation and dislocation strengthening is increased.The decrease of ductile-brittle transition temperature from−103 to−116℃is attributed to the decrease in equivalent grainsize and the increase of high-angle grain boundary misorientation,which hinders the initiation and propagation of cracks.When the mass fraction of Ti is 0.05%,the strength and cryogenic toughness can be improved synergistically,which alsoprovides a theoretical basis and experimental reference for exploring the more excellent combination of strength andcryogenic toughness of marine 10Ni5CrMoV steel.

组织类型对Ti-Mo高强钢耐蚀性能的影响

利用周期浸润腐蚀试验机、电化学工作站测试了Ti-Mo高强钢的耐蚀性能,结合光学显微镜、X射线衍射仪、扫描电子显微镜、原子力显微镜的检测结果探讨了组织类型对耐蚀性能的影响规律。结果表明:随着实验钢中珠光体与贝氏体比例的降低,锈层生长速度减慢,内锈层厚度占比提高,锈层的致密程度以及与材料的结合能力得到改善,腐蚀失重率下降;裸钢的自腐蚀电流密度下降,电荷转移电阻增强,耐蚀性能提升。测量了实验钢的微观组织电位,铁素体电位高于贝氏体/珠光体电位。由于不同组织之间会形成微观腐蚀电池,电偶腐蚀强度是影响实验钢腐蚀速率的主要因素;减少Ti-Mo高强钢中贝氏体/珠光体的体积分数,可以改善组织均匀性,抑制电偶腐蚀,提高耐蚀性能。