材料期刊网

Influence of Cr, Mn and Mo Addition on Structure and Properties of V Microalloyed Medium Carbon Steels

材料科学技术（英）

关键词: 力学性能测试 , V微合金化 , 中碳结构钢 , 中碳钢 , 针状铁素体 , 铬 , 奥氏体化温度 , 锰

Processing of Ultralow Carbon Pipeline Steels with Acicular Ferrite

Furen XIAO , Mingchun ZHAO , Yiyin SHAN , Bo LIAO , Ke YANG

材料科学技术（英）

Acicular ferrite microstructure was achieved for an ultralow carbon pipeline steel through the improved thermomechanical control process (TMCP), which was based on the transformation process of deformed austenite of steel. Compared with commercial pipeline steels, the experimental ultralow carbon pipeline steel possessed the satisfied strength and toughness behaviors under the current improved TMCP, although it contained only approximately 0.025% C, which should mainly be attributed to the microstructural characteristics of acicular ferrite.

关键词: Pipeline steel , null , null

Effect Of Zr Addition To Ti-Killed Steel On Inclusion Formation And Microstructural Evolution In Welding Induced Coarse-Grained Heat Affected Zone

F. Chai , C.F. Yang , H. Su , Y.Q. Zhang , null , null

金属学报(英文版)

Effects of Zirconium on the chemical component and size distribution of Ti-bearing inclusions, favored the grain refinement of the welding induced, coarse-grained heat affected zone (CGHAZ) with enhanced impact toughness in Ti-killed steels, which were examined based on experimental observations and thermodynamic calculations. It indicated that the chemical constituents of inclusions gradually varied from the Ti-O oxide to the Ti-O+Zr-O compound oxide and a single phase of the ZrO 2 oxide, as the Zr content increased from zero to 0.0100\%. A trace of Zr (0.0030 %--0.0080n %, depending on the oxygen content in liquid steel) provided a large amount of nucleating core for Ti oxide because of the larger specific density of ZrOn 2 oxide, and produced a small size distribution of the inclusions favorable for acicular ferrite transformation with a high nucleation rate in the CGHAZ, and a high volume fraction of acicular ferrite was obtained in the CGHAZ, with enhanced impact toughness. Otherwise, a high content of Zr (~0.0100 %) produced a single phase ZrO 2, which was impotent to nucleate acicular ferrite, and a microstructure composed of ferrite side plate and grain boundary ferrite developed in the CGHAZ. The experimental results were confirmed by thermodynamic calculations.

关键词: Nonmetallic inclusions , null , null