含铌、钒、钛EQ47海洋平台用钢的高温塑性研究

EQ47钢是最常用海洋平台用钢之一，为了生产出符合质量要求的EQ47钢，需要对EQ47钢生产工艺进行研究；钢的高温塑性可以影响铸坯的质量，为了保证铸坯质量，需要对含铌、钒、钛EQ47海洋平台用钢的高温塑性进行研究。采用Gleeble-1500D热模拟机进行高温塑性试验，分析了EQ47钢高温塑性特点，断裂机理，以及铌、钒、钛对高温塑性的影响。结果表明：钢存在2个脆性区间，即第Ⅰ脆性区间为1270-1350℃，第Ⅲ脆性区间为600-900℃；试验钢的断裂形式有穿晶断裂和沿晶断裂；钢中的铌、钒、钛及其析出物均对钢的高温塑性产生影响。

Hot ductility and plasticity of EQ47 steel plate containing Nb,V, Ti used for offshore platform

EQ47 steel is one of the most commonly used steel plate for offshore platform. In order to produce EQ47 steel conforming to the quality requirements ,its manufacturing technique is studied to find out that the hot ductility and plasticity of the steel can affect the quality of billet. In order to guarantee the quality of billet in the production process, the hot ductility and plasticity test is carried out on Gleeble-1500D heat stress/strain test machine to analyze the features of the hot ductility and plasticity , fracture mode and the influence of the ductility and plasticity on Nb, V ,Ti . The results indicate that there are two brittle zones ：the first brittle zones is between 1 270 ℃ and 1 350 ℃, the third brittle zones is between 600 ℃ and 900 ℃; the fracture modes of steel are transgranular fracture and intergranular fracture;Nb,V,Ti and their precipitations have great effect on the hot ductility and plasticity.