【摘要】：近年來(lái)我國(guó)對(duì)非調(diào)質(zhì)鋼的研究與應(yīng)用高度重視,但國(guó)內(nèi)生產(chǎn)的F+P型高強(qiáng)度、高韌性非調(diào)質(zhì)鋼的研究和應(yīng)用都較少,需要對(duì)其展開進(jìn)一步細(xì)致的研究工作。本文針對(duì)南鋼生產(chǎn)的F45MnVS高強(qiáng)度非調(diào)質(zhì)鋼的需求,從非調(diào)質(zhì)鋼的熱軋工藝,化學(xué)成分,非調(diào)質(zhì)鋼強(qiáng)度和韌性入手,對(duì)F45MnVS非調(diào)質(zhì)鋼的動(dòng)態(tài)CCT曲線,顯微組織、常規(guī)力學(xué)性能、動(dòng)態(tài)再結(jié)晶行為、對(duì)該鋼進(jìn)行調(diào)質(zhì)處理正交實(shí)驗(yàn),與非調(diào)質(zhì)鋼的性能進(jìn)行對(duì)比、以及F45MnVS鋼的終軋力學(xué)性能計(jì)算進(jìn)行了重點(diǎn)研究。論文的主要內(nèi)容如下:1.利用Gleeble-2000對(duì)F45MnVS鋼進(jìn)行動(dòng)態(tài)CCT實(shí)驗(yàn),測(cè)定了F45MnVS鋼的奧氏體相變溫度,AC1=720℃,AC3=774℃;F45MnVS鋼的動(dòng)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(shí),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(shí),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(duì)F45MnVS鋼進(jìn)行單道次壓縮實(shí)驗(yàn)。根據(jù)實(shí)驗(yàn)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(jì)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(shí)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(qiáng)度有余而韌性不足。通過(guò)對(duì)F45MnVS鋼進(jìn)行調(diào)質(zhì)處理實(shí)驗(yàn),與非調(diào)質(zhì)的性能進(jìn)行對(duì)比。得出結(jié)論:本正交實(shí)驗(yàn)設(shè)計(jì)中的最優(yōu)工藝為將實(shí)驗(yàn)鋼加熱到800℃,保溫20min,以水為介質(zhì),進(jìn)行淬火;再將實(shí)驗(yàn)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(xì)小的回火索氏體組織,韌性最好,沖擊功AKu值達(dá)到155J。4.由電子結(jié)構(gòu)計(jì)算的方法,根據(jù)F45MnVS鋼的化學(xué)成分,終軋奧氏體晶粒度,結(jié)合F45MnVS鋼軋制過(guò)程中的固溶強(qiáng)化,細(xì)晶強(qiáng)化,彌散強(qiáng)化,析出強(qiáng)化,珠光體轉(zhuǎn)變,計(jì)算出F45MnVS鋼的終軋力學(xué)性能:σb值為901.65MPa,?值為14.75%,AKu值為53.58J,與實(shí)驗(yàn)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(hào)：2174528