含P高强IF钢的高温力学性能  

High Temperature Mechanical Properties of P-Containing High Strength IF Steel

作　　者：闫永其[1] 崔衡[1] 王征[1] 赵爱民[1] 

机构地区：[1]北京科技大学冶金工程研究院,北京100083

出　　处：《材料研究学报》2015年第8期602-606,共5页Chinese Journal of Materials Research

基　　金：北京市青年英才计划YETP0411;中央高校基本科研业务费专项资金FRF-TP-14-102A2资助~~

摘　　要：使用Gleeble3500热模拟试验机测定零塑性温度(ZDT)、零强度温度(ZST)及最大抗拉强度随温度的变化,用扫描电镜观察分析不同拉伸温度下的断口形貌,使用THERMO-CALC软件计算其冷却过程中的相变及析出相,研究了含P高强IF钢的高温力学性能。结果表明,该钢种的ZDT和ZST分别为1420℃和1445℃,第Ⅰ脆性区间为1400℃-熔点,不存在第Ⅲ脆性区间,铸坯表面裂纹不是在矫直过程中形成的;铸坯的最大抗拉强度随着拉伸温度的升高而降低,在1300℃以上最大抗拉强度均低于5.3 MPa;高强IF钢连铸坯冷却至500℃-200℃时析出大量Fe3P,可能导致铸坯冷脆开裂。采用热装工艺,可以降低高强IF钢铸坯表面横裂纹出现的机率。The high temperature mechanical properties of P-contained high strength interstitial free （IF） steel were investigated using Gleeble3500 thermal simulation testing machine, in terms of zero ductility temperature （ZDT）, zero strength temperature （ZST） and the relationship of tensile strength with temperature. The fractured surfaces at different tensile temperatures were characterized by means of scanning electron microscope. The phase transition temperature interval was deduced by the THERMO- CALC software. The results show that the ZDT and ZST of the steel are 1420℃ and 1445℃, respectively. The brittleness temperature interval I is from 1400℃ to the melting point, and there is no the brittleness temperature interval Ⅲ. The transverse cracks on the surface of casting blank did not occur during the straightening process. The tensile strengths decrease with the increasing temperature in the test temperature range, and which are lower than 5.3 MPa above 1300~C. The result of THERMO-CALC calcula- tion shows that, with the specimens cooling from 500℃ to 400℃, Fe3P precipitates out in the a-Fe matrix, which may results in cold short. The transverse cracks on the continuous casing （CC） slab could dramatically be reduced by Hot-charging Technology.

关 键 词：金属材料 高温力学性能 高温拉伸 含P高强IF钢 THERMO-CALC 相变 

分 类 号：TF777[冶金工程—钢铁冶金]