本文關(guān)鍵詞： 微合金鋼 連鑄坯 第Ⅲ脆性區(qū) 機理 裂紋　出處：《鋼鐵研究學(xué)報》2017年02期 　論文類型：期刊論文

【摘要】：為研究微合金鋼第Ⅲ脆性區(qū)形成機理及其影響因素,控制連鑄坯的表面裂紋,采用Gleeble熱力模擬機測定了S355微合金鋼在不同溫度下的抗拉強度及斷面收縮率。使用掃描電鏡對拉伸斷口進行觀察分析,同時采用透射電鏡對析出物進行觀察分析。在此基礎(chǔ)上對拉伸試樣進行金相實驗,對第二相析出進行熱力學(xué)計算,分析了組織狀態(tài)及第二相析出規(guī)律對脆性區(qū)的影響。結(jié)果表明,在第Ⅲ脆性區(qū)(660~850℃)內(nèi),拉伸斷口呈冰糖狀,韌窩較淺,形貌表現(xiàn)為沿晶脆性斷裂。鐵素體網(wǎng)膜沿奧氏體晶界優(yōu)先析出、第二相沿晶界析出是第Ⅲ脆性區(qū)形成的主要原因。
[Abstract]:In order to study the formation mechanism of the third brittleness zone of microalloyed steel and its influencing factors, the surface crack of continuous casting billet was controlled. Tensile strength and cross section shrinkage of S355 microalloyed steel at different temperatures were measured by Gleeble thermal simulator. Tensile fracture was observed and analyzed by scanning electron microscope (SEM). At the same time, the precipitates were observed and analyzed by transmission electron microscope. On the basis of this, metallographic experiments were carried out on the tensile samples, and thermodynamic calculations of the second phase precipitation were carried out. The effect of the structure state and the precipitation law of the second phase on the brittle zone is analyzed. The results show that the tensile fracture surface is ice-sugar shaped and the dimple is shallow in the third brittleness zone (660,850 鈩，

本文編號：1443360