摘要
通过工艺控制得到了不同尺寸及分布特征的析出相,研究了其对再结晶织构的影响.结果表明:降低精轧温度有利于尺寸更加细小、分布更加弥散的析出相TiC的形成,经冷轧及退火后这种析出相分布特征可遗传至冷轧退火板;粗大、稀疏析出相的样品具有较强的γ纤维再结晶织构;细小、弥散的析出相有助于随机取向再结晶晶核的形成,抑制再结晶晶粒的长大,从而弱化了γ纤维再结晶织构及恶化了冷轧退火板成形性能;析出相对随机取向晶粒形核的作用及晶界迁移的钉扎作用是控制铁素体不锈钢再结晶织构的重要因素之一.
Improved mechanical properties of ferritic stainless steels （FSSs）, such as toughness and high temperature or creep resistance, have been attained through the addition of stabilizing elements such as Nb and/or Ti. Therefore, stabilized ferritic stainless steels are good candidates to replace the conventional Cr-Ni austenitic stainless steels for specific applications to save the higher price of Ni. As compared to austenitic stainless steels, however, ferritic stainless steels possess lower formability which is closely depends on the γ-fiber recrystallization texture. Hence, improvement of formability is desired for further wide applications of FSSs. The stabilizing effects of alloying elements work by consuming not only the interstitial atoms in solid solution but also forming the carbide and nitride precipitates such as TiC, TiN and NbC. The precipitation takes place in steel making processes such as slab reheating, hot rolling and coiling. The parameters involving these processes have their effects on the size, shape and distribution of the precipitates that influence the γ fiber recrystallization texture. Many papers intended to clarify the effect of precipitates. However, there were differences concerning the effect of precipitates, which may hinder further improvement of formability. In the present paper, precipitate size and dispersion were changed by controlling hot rolling processes and the effect of precipitate size and dispersion on the development of recrystallizaton texture in a 17%Cr ferritie stainless steels was investigated. Mechanical properties were measured by tensile tests.The characteristics of precipitate were observed by transmission electron microscopy, and X-ray diffrac- tion was used to characterize texture evolution processes. The results show that low temperature finish rolling promotes the formation of a large number of fine and dispersed TiC precipitates in the hot band. After rolling and annealing, the state of fine and dispersed precipitation can be inherited in the cold roiled and annealed sheets. Strong γ-fiber recrystallizaton texture is developed in the specimen with sparsely distributed and coarse precipitates. Fine and dispersed precipitates promote the nucleation of randomly oriented grains, strongly suppress the growth of reerystallized grain, and thereby weakening γ-fiber reerystallizaton texture and impairing the formability of the cold rolled and annealed sheets. The precipitates have significant effects on the nucleation of randomly oriented grains and pinning grain boundary mobility during recrystallization annealing after cold rolling, which plays an important roles in controlling the γ-fiber recrystallizaton texture in a ferritic stainless steels.
出处
《金属学报》
SCIE
EI
CAS
CSCD
北大核心
2012年第10期1166-1174,共9页
Acta Metallurgica Sinica
基金
国家自然科学基金项目50734002和51004035
中央高校基本科研业务费专项项目N100507002资助~~
关键词
17%Cr铁素体不锈钢
析出相
织构
再结晶
17%Cr ferritic stainless steel, precipitate, texture, recrystallization
