摘要
在普通耐候钢Q450NQR1成分的基础上,通过理论计算,设计出一种钛含量为0.04%～0.10%、屈服强度为520～750 MPa的高强度耐候钢。按照成分设计要求,采用高频真空感应炉在1 873 K条件下熔炼钢样,并对不同钛加入量的钢样进行成分和组织结构分析。结果表明,熔炼的钢样中氧含量为(17～26)×10-6,氮含量为(12～66)×10-6,钛含量为0.006 1%～0.059 0%;钢样组织主要由铁素体和珠光体构成,随着钢中钛含量的增加,晶粒明显细化,钢组织渐趋均匀。SEM分析表明,钢中长方体的TiN夹杂,是以球形的Al2O3、MgO和钛氧化物夹杂为核心生长的,必要时在微合金化处理之前将钢中的氧含量降低到一定程度。
Based on the composition of common Q450NQR1 weathering steel,titanium micro-alloyed steel,with titanium content at the range of 0.04%～0.10% and the yield strength of 520～750 MPa,was designed with theoretical calculation.The steel was smelt in a high frequency vacuum inductive furnace at 1 873 K to accord with the design of the components.And the component and microstructure of the smelt steel samples with different titanium contents is analyzed.The oxygen content is（17～26）×10-6 while that of nitrogen content fluctuates being（12～66）×10-6,and the titanium content in the smelt steel is in the range of 0.006 1%～0.059 0%.The microstructure of the samples mainly consists of ferrite and pearlite,and grain size is obviously refined and microstructure presents gradual uniformity with the increase of titanium contents added in the steel.SEM analysis shows that TiN cuboid inclusion grows by using spherical Al2O3,MgO and titanium oxide inclusions as nucleation.So it is essential to reduce oxygen contents in the steel to a certain degree before microalloying.
出处
《武汉科技大学学报》
CAS
2010年第5期516-521,共6页
Journal of Wuhan University of Science and Technology
基金
湖北省自然科学创新群体基金资助项目(2008CDA010)
关键词
耐候钢
钛微合金化
成分设计
细化晶粒
沉淀强化
weathering steel
titanium microalloyed
composition design
refined grain
precipitation strength
