發(fā)布時(shí)間：2019-01-01 07:42

【摘要】：船舶工業(yè)的快速發(fā)展,對(duì)船舶用鋼提出了更高的要求。目前高品質(zhì)船舶用鋼的制造主要是通過(guò)Nb、Ti等元素的微合金化作用并結(jié)合TMCP軋制技術(shù)。近年來(lái)隨著鋼潔凈度的提高,稀土在鋼中的應(yīng)用越來(lái)越受到重視。大量的研究表明,輕稀土元素可以改善鋼的組織并且提高鋼材的綜合性能。本文以E36船板鋼為研究對(duì)象,通過(guò)喂線(xiàn)的方式在E36船板鋼的精煉過(guò)程中喂入釔基稀土包芯線(xiàn),研究釔基稀土對(duì)E36船板鋼組織性能及相變規(guī)律的影響。具體研究?jī)?nèi)容和結(jié)論如下:(1)釔基稀土對(duì)E36鋼相變規(guī)律的影響主要有:(1)添加釔基稀土以后,E36鋼的AC1和AC3分別由710℃、875℃提高到730℃、885℃;(2)E36RE鋼在組織中的貝氏體量有所減少;(3)E36RE鋼在不同冷卻速度下組織的硬度有所降低;(4)E36RE鋼CCT曲線(xiàn)較E36鋼有所左移,貝氏體的轉(zhuǎn)變溫度有所提高。(2)添加釔基稀土后,E36RE鋼較E36鋼珠光體量有所增加,且游離滲碳體較彌散;并且E36R鋼較E36鋼珠光體片層間距縮小,且珠光體表現(xiàn)為退化態(tài)。稀土元素在晶界等缺陷處偏聚和過(guò)冷度增加是珠光體增加的主要原因。添加釔基稀土后,鋼液過(guò)冷度增加和稀土元素在鋼中的固溶,阻礙了C原子的擴(kuò)散遷移,從而限制了滲碳體的形核速度與長(zhǎng)大速度,細(xì)化了珠光體組織。(3)釔基稀土E36鋼中的夾雜物由變質(zhì)作用。一方面是對(duì)夾雜物形態(tài)的變質(zhì),添加稀土前,鋼中的夾雜物主要是CaO、Al2O3等金屬夾雜物和MnS夾雜物,添加釔基稀土后,鋼中夾雜物變質(zhì)為稀土復(fù)合夾雜物。另一方面是改善了夾雜物的尺寸,添加稀土前E36鋼橫向夾雜物主要為20微米左右的長(zhǎng)條狀MnS夾雜物,添加稀土以后,E36RE鋼中夾雜物主要為小于5μm以?xún)?nèi)的球狀稀土復(fù)合夾雜物。(4)釔基稀土對(duì)E36鋼的沖擊性能有明顯的改善,主要體現(xiàn)在:(1)對(duì)沖擊韌性有良好的改善,尤其是低溫沖擊韌性。(2)減小了縱向和橫向沖擊功值的差異,降低了沖擊功的縱橫比,改善了各向異性。組織的細(xì)化及夾雜物的改性是影響沖擊性能的主要原因。
[Abstract]:With the rapid development of ship industry, higher requirements are put forward for ship steel. At present, the manufacture of high quality marine steel is mainly through the microalloying of elements such as Nb,Ti and TMCP rolling technology. In recent years, with the improvement of steel cleanliness, the application of rare earth in steel has been paid more and more attention. A large number of studies have shown that light rare earth elements can improve the structure of steel and improve the comprehensive properties of steel. In this paper, the yttrium base rare earth cored wire was fed to E36 ship plate steel in the process of refining by feeding wire to study the effect of yttrium base rare earth elements on the microstructure and phase transformation of E36 ship plate steel. The specific research contents and conclusions are as follows: (1) the effects of yttrium base rare earth on the transformation of E36 steel are as follows: (1) after adding yttrium base rare earth, the AC1 and AC3 of E36 steel increase from 710 鈩，

本文編號(hào)：2397215