【摘要】：采用拉力試驗機、金相顯微鏡、透射電鏡、X射線衍射儀、掃描電鏡和沖擊試驗機對富氮釩鈮微合金化控冷工藝制備的600MPa級抗震鋼筋的力學性能、顯微組織、析出相、斷口形貌、沖擊韌性及時效性進行了研究。結果表明:該鋼筋具有良好的強韌性、抗震性及低應變時效性,力學性能優(yōu)異。該鋼的顯微組織為鐵素體+珠光體+少量細小貝氏體(含量5%~10%),組織配比及形態(tài)較好。該鋼的鐵素體基體、晶界及位錯線上析出了大量尺寸2~20nm的細小彌散的V(CN)、Nb(CN)析出相,其析出相數(shù)量分別占總釩、總鈮量的65%以上,起到了較好的沉淀強化及細化晶粒作用。該鋼筋拉伸斷口呈韌窩狀,韌脆轉變溫度低于-30℃,具有較好的塑韌性和低溫沖擊韌性。
[Abstract]:The mechanical properties, microstructure, precipitation phase, fracture morphology of 600MPa grade anti-seismic steel bar prepared by means of tensile testing machine, metallographic microscope, transmission electron microscope (TEM), X-ray diffractometer (TEM), scanning electron microscope (SEM) and impact test machine (IPT) were studied. The impact toughness and time effect are studied. The results show that the steel bar has good strength and toughness, seismic resistance, low strain time effect and excellent mechanical properties. The microstructure of the steel is a small amount of fine ferrite pearlite bainite (5% 10%), and the microstructure and morphology of the steel are better. In the ferrite matrix, grain boundary and dislocation line, a large number of fine 2~20nm dispersed V (CN) NB (CN) precipitates have been precipitated. The precipitated phases account for more than 65% of the total vanadium and the total niobium content, which plays a better role in precipitation strengthening and grain refinement. The tensile fracture of the steel bar is dimple, and the ductile and brittle transition temperature is lower than -30 鈩，

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