Effect of Cooling Start Temperature on Microstructure and Mechanical Properties of X80 High Deformability Pipeline Steel

The effect of cooling （laminar cooling） start temperature on the phase constitution was analyzed by quanti- tative metallography. The martensite/austenite （M/A） island distribution was fixed by colour metallography. The strength and uniform elongation of the steels were tested with quasi-static tensile testing machine. The in-coordinate deformation of the soft and hard phases was analyzed using FEM. The results indicate that when the cooling start temperature is 690 ℃, the mechanical properties are the best, meeting the requirements of X80 high deformability pipeline steel.

VUHZ检测控制系统在ESP产线的应用

结晶器钢水液位检测和控制是连铸机生产控制的核心环节之一,稳定的结晶器液位对提高铸坯内部和表面质量、避免保护渣及其他非金属夹杂物卷入、减少漏钢或溢钢等生产事故具有重要意义。尤其是高拉速、高通钢量的ESP薄板坯连铸机,其对液位检测和控制的精度要求更高。以往在ESP连铸机使用的结晶器液位传感器均为NKK系统,其具有成熟的应用经验。针对VUHZ液位检测系统首次在ESP连铸机上的应用,通过优化系统控制参数、信号补偿、冷却水系统等解决了影响VUHZ传感器液位检测的问题。实践表明,在高拉速条件下,VUHZ系统液位控制精度及液位波动能够满足现场工艺生产要求。