论文部分内容阅读
铌、钛微合金化钢连铸坯高温变形试样中主要有三类碳、氮化合物析出：（１）高温下析出的粗大块状ＴｉＮ析出物；（２）９５０～９００℃区间沿晶界和在晶粒基体内部析出的微细Ｎｂ（Ｃ，Ｎ）动态析出物；（３）温度低于９００℃后Ｎｂ（Ｃ，Ｎ）依附在ＴｉＮ颗粒上生成的复合析出物．在９５０～９００℃区间析出的微细Ｎｂ（Ｃ，Ｎ）是造成此温度区间试样延塑性急剧降低的主要原因．由于氮优先与钛反应，减少了低温时Ｎｂ（Ｃ，Ｎ）和ＡｌＮ的析出量，使铌、钛微合金化钢在８５０℃Ｃ～Ａｒ３温度之间延塑性没有进一步降低．
There are mainly three types of carbon and nitrogen compounds precipitated in high temperature deformation specimens of niobium and titanium microalloyed steel continuous casting billet: (1) coarse bulk TiN precipitates precipitated at high temperature; (2) (C, N) dynamic precipitates precipitated inside the grain matrix, and (3) composite precipitates formed by the adhesion of Nb (C, N) to TiN particles at temperatures below 900 ° C. The fine Nb (C, N) precipitated in the 950-900 ° C interval is the main reason causing the sharp decrease of the ductility of the sample in this temperature range. Since nitrogen preferentially reacts with titanium, the amount of Nb (C, N) and AlN precipitated at low temperatures is reduced, so that the ductility of niobium and titanium microalloyed steels does not decrease further from 850 C to Ar3 temperature.