铌钛微合金钢异型坯高温塑性研究

STUDY ON HIGH TEMPERATURE PLASTICITY OF Nb-Ti MICROALLOYED BEAM BLANKS

在GLLEEBLE3800热模拟试验机上进行了铌钛复合微合金化钢异型坯的高温拉伸试验,并对断口形貌进行了分析,确定了钢材的脆性温度区,第I脆性区的温度范围为1 300℃至熔点,高温塑性区的温度范围为950~1 300℃,第Ⅲ脆性区的温度范围为700~900℃,高温塑性区为微孔聚集韧性断裂,呈现典型的韧窝结构,在第Ⅲ脆性区为准解理断裂,呈现典型的河流花样结构。

The high temperature tensile test of Nb-Ti composite microalloyed steel beam blank was carried out on GLEEBLE 3800 Thermal Mechanical Simulator, and the fracture morphology was analyzed. The brittle temperature zone of steel was determined. The temperature range of the first brittle zone was 1 300 ℃ to melting point, the temperature range of the high temperature plastic zone was 950 ℃ to 1 300 ℃, and the temperature of the third brittle zone was determined. The degree ranges from 700 ℃ to 900 ℃. The high temperature plastic zone is microporous aggregation ductile fracture, showing typical dimple structure, quasi cleavage fracture in Ⅲ brittle zone and typical river pattern structure.