材料期刊网

<正> 本文采用X光衍射方法和金相观察,研究在不同Q值(减壁率与减径率之比值)下,静液挤压Zr-2.5％Nb管材的织构与加工Q值、氢化物取向分布之间的关系,为调整和控制工艺提供参数依据。 将Zr-2.5％Nb合金加工成挤压管坯,经700℃退火处理后,在管坯内外表面涂以润滑剂,并于13-15kPa压力下冷静挤成管材。切取管材塑性变形区余部作测定试样。沿垂直于轴向变形区切割试样,后经HNO_3,HF和H_2O溶液浸蚀除去表面变形层供X射线测定织构用。

The pole figure and inverse pole figure of the hydrostatically extruded Zr-2.5%Nb alloy tube with various Q values (the reduction ratio of wall thickness to diameter) were examined by X-ray diffration. It is resulted that the texture parameter, V_48 is related linearly to Q value. The texture gradient along the direction of tube wall thickness seems to be no appreciable. When the Q value changes from 0.2 to 2.59, the hydride is distributed into a circular direction via radial, and the corresponding texture parameter V_48 decreases from 0.53 to 0.28.The circular hydride distribution may be re-orientated under circular tensile stress after cyclic heat-treatment. The threshold of the stress re-orientaton of hydrideis rather high for tube with radial basal pole texture.