本文關鍵詞： 控軋控冷 Mn-Ti型高強鋼 拉伸性能 沖擊韌性 Gleeble-3800　出處：《中北大學》2017年碩士論文　論文類型：學位論文

【摘要】：鋼鐵產業(yè)是我國國民經濟的支柱性產業(yè),目前我國鋼鐵產業(yè)正處于化解產能過剩的關鍵時期,另外國內外眾多領域用鋼也提出了更高強度、更好塑性以及一定韌性和良好焊接性的要求�？剀埧乩涔に囎鳛�21世紀一項新技術,控軋控冷技術下低碳微合金化高強度鋼不僅在改善鋼材的綜合性能方面取得了明顯的效果,在鋼鐵生產上得到廣泛應用,而且控軋控冷技術在減少能源消耗發(fā)展制造綠色鋼鐵材料發(fā)揮了重要作用,是目前各國鋼鐵學者的研究熱點。本文主要研究了控軋控冷工藝下低碳微合金Mn-Ti型鋼在室溫拉伸變形、低溫沖擊及熱壓縮狀態(tài)下,得到實驗鋼在不同實驗參數(shù)下的微觀組織和力學性能,分析其微觀組織的演變過程,及組織對實驗鋼力學性能的影響,結合實驗鋼具體的使用條件和要求,為鋼鐵實際生產過程控軋控冷工藝參數(shù)制定提供理論依據,具體研究內容如下:(1)研究Mn-Ti型實驗鋼分別在20℃/s、2℃/和0.2℃/s不同冷卻速度下室溫拉伸變形過程微觀組織演變及抗拉強度,確定了實驗鋼在冷卻速度下的相變機制,得到Mn-Ti型實驗鋼隨著冷卻速度增加,屈服強度、抗拉強度、屈強比顯著升高,當冷卻速度達到20℃/s時,抗拉強度最高可達到998MPa。(2)Mn-Ti型高強鋼控軋控冷工藝后控冷至320℃、280℃、240℃、170℃和100℃進行卷取,觀察并研究了試驗鋼的微觀組織對沖擊性能的影響,分析了不同卷取溫度下多種形態(tài)鐵素體、位錯、M-A島對鋼材沖擊性能的控制機制。結果表明,隨著試驗鋼卷取的溫度從320℃降到100℃,試驗鋼微觀組織中位錯結構和細小M-A島的多邊形鐵素體最有利于沖擊吸收能量的增加;當板條狀鐵素體和大尺寸M-A島出現(xiàn)時,沖擊吸收能量下降;特別是較大長度的板條狀鐵素體形成時,試驗鋼的沖擊吸收能量下降至最小。(3)利用Gleeble-3800熱模擬在應變速率為1s-1變形溫度在760℃、810℃、860℃、910℃、960℃和860℃下應變速率分別為0.1s-1、1s-1、5s-1、10s-1進行熱壓縮實驗,研究不同應變速率和變形溫度熱變形參數(shù)對Mn-Ti型多相高強鋼變形后冷卻時相變過程和微觀組織特征的影響,以準確地控制變形后的組織,優(yōu)化生產工藝及微觀組織。
[Abstract]:Iron and steel industry is the pillar industry of our national economy. At present, China's iron and steel industry is in the key period of resolving overcapacity. In addition, many domestic and foreign fields of steel also put forward a higher strength. In 21th century, the controlled rolling and cooling process is a new technology. Low carbon microalloyed high strength steel under controlled rolling and cooling control technology has not only achieved obvious results in improving the comprehensive properties of steel, but also has been widely used in iron and steel production. Moreover, controlled rolling and cooling control technology plays an important role in reducing energy consumption and developing green iron and steel materials. At present, it is the research hotspot of iron and steel scholars all over the world. In this paper, low carbon microalloyed Mn-Ti section steel under controlled rolling and controlled cooling process is studied under room temperature tensile deformation, low temperature impact and hot compression. The microstructure and mechanical properties of experimental steel under different experimental parameters were obtained. The evolution process of microstructure and the effect of microstructure on mechanical properties of experimental steel were analyzed. This paper provides a theoretical basis for the formulation of process parameters of controlled rolling and controlled cooling in the actual production process of iron and steel. The specific research contents are as follows: 1) the Mn-Ti type experimental steel is studied at 20 鈩，

本文編號：1450178