【摘要】：近年來我國對非調(diào)質(zhì)鋼的研究與應(yīng)用高度重視,但國內(nèi)生產(chǎn)的F+P型高強度、高韌性非調(diào)質(zhì)鋼的研究和應(yīng)用都較少,需要對其展開進一步細致的研究工作。本文針對南鋼生產(chǎn)的F45MnVS高強度非調(diào)質(zhì)鋼的需求,從非調(diào)質(zhì)鋼的熱軋工藝,化學成分,非調(diào)質(zhì)鋼強度和韌性入手,對F45MnVS非調(diào)質(zhì)鋼的動態(tài)CCT曲線,顯微組織、常規(guī)力學性能、動態(tài)再結(jié)晶行為、對該鋼進行調(diào)質(zhì)處理正交實驗,與非調(diào)質(zhì)鋼的性能進行對比、以及F45MnVS鋼的終軋力學性能計算進行了重點研究。論文的主要內(nèi)容如下:1.利用Gleeble-2000對F45MnVS鋼進行動態(tài)CCT實驗,測定了F45MnVS鋼的奧氏體相變溫度,AC1=720℃,AC3=774℃;F45MnVS鋼的動態(tài)CCT曲線,主要有三種組織轉(zhuǎn)變:(1)冷速較低,冷速范圍為0.1℃/s~5℃/s時,主要發(fā)生F+P轉(zhuǎn)變;(2)中等冷速,冷速范圍為7℃/s~10℃/s時,可以看出組織為貝氏體組織,發(fā)生貝氏體轉(zhuǎn)變;(3)冷速為12℃/s及以上,可以看出組織中的馬氏體組織,發(fā)生馬氏體轉(zhuǎn)變。2.利用Gleeble-2000對F45MnVS鋼進行單道次壓縮實驗。根據(jù)實驗數(shù)據(jù)繪制了不同熱變形條件下F45MnVS鋼的應(yīng)力-應(yīng)變曲線,剖析了變形條件與變形抗力以及再結(jié)晶之間的聯(lián)系;計算出F45MnVS鋼的再結(jié)晶激活能為418.583KJ/mol,給出了F45MnVS鋼熱變形時的變形抗力公式和變形本構(gòu)方程。3.F45MnVS鋼的組織為F+P,用于制造汽車軸類零件,但其強度有余而韌性不足。通過對F45MnVS鋼進行調(diào)質(zhì)處理實驗,與非調(diào)質(zhì)的性能進行對比。得出結(jié)論:本正交實驗設(shè)計中的最優(yōu)工藝為將實驗鋼加熱到800℃,保溫20min,以水為介質(zhì),進行淬火;再將實驗鋼加熱到600℃,保溫60min,取出空冷。由此調(diào)質(zhì)工藝處理后,F45MnVS鋼獲得細小的回火索氏體組織,韌性最好,沖擊功AKu值達到155J。4.由電子結(jié)構(gòu)計算的方法,根據(jù)F45MnVS鋼的化學成分,終軋奧氏體晶粒度,結(jié)合F45MnVS鋼軋制過程中的固溶強化,細晶強化,彌散強化,析出強化,珠光體轉(zhuǎn)變,計算出F45MnVS鋼的終軋力學性能:σb值為901.65MPa,?值為14.75%,AKu值為53.58J,與實驗值有較好的吻合。
[Abstract]:In recent years, China attaches great importance to the research and application of non-quenched and tempered steels, but the research and application of F-P type high strength and high toughness non-quenched and tempered steels produced in China are few, so it is necessary to carry out further and detailed research work on them. In this paper, according to the demand of F45MnVS high strength non-quenched and tempered steel produced by Nangang, the dynamic CCT curve, microstructure and conventional mechanical properties of F45MnVS non-quenched and tempered steel are studied from the aspects of hot rolling process, chemical composition, strength and toughness of non-quenched and tempered steel. The dynamic recrystallization behavior of the steel was studied by means of the orthogonal test of tempering and tempering, and the comparison between the properties of the steel and the non-quenched and tempered steel, as well as the calculation of the final rolling mechanical properties of F45MnVS steel. The main contents of the thesis are as follows: 1: 1. The austenitic transformation temperature of F45MnVS steel was measured by dynamic CCT test with Gleeble-2000. The dynamic CCT curves of F45MnVS steel were measured at 774 鈩，

本文編號：2174528