【摘要】：隨著航天航空、鐵路、汽車、工程機械和電子等行業(yè)的快速發(fā)展，國內(nèi)彈簧鋼的需求量日益增多。雖然我國彈簧鋼的生產(chǎn)工藝技術(shù)和產(chǎn)能已與國內(nèi)消費量匹配，但中高級別彈簧鋼的進口量仍居高不下，嚴重阻礙我國彈簧鋼產(chǎn)業(yè)、鋼鐵企業(yè)品種結(jié)構(gòu)和國內(nèi)經(jīng)濟的可持續(xù)、健康發(fā)展。彈簧鋼在特殊環(huán)境（如長期承受拉、壓、彎、扭和沖擊等載荷作用）下工作，不僅要具有穩(wěn)定的化學(xué)成分、純凈的鋼質(zhì)，而且需具備微細的基體組織和優(yōu)異的力學(xué)性能。根據(jù)目前國際、國內(nèi)彈簧鋼的生產(chǎn)實際和冶金理論前沿研究成果，本研究圍繞“提高鋼液潔凈度、控制夾雜物性狀與鋼材組織、提高彈簧鋼使用性能”等子課題，以應(yīng)用廣泛的65Mn鋼為研究對象，進行較為系統(tǒng)的基礎(chǔ)理論研究。 為改善65Mn彈簧鋼微觀組織、夾雜物性狀和力學(xué)性能，通過冶金熱力學(xué)理論計算和實驗室規(guī)模研究，在定量表征彈簧鋼顯微組織、夾雜物性狀和力學(xué)性能等隨微量Ce變化規(guī)律的基礎(chǔ)上，分析、探討精煉過程中Ce含量在0.65%C-0.35%Si-1.20%Mn系鋼液中夾雜物變性機理、含Ce夾雜物顆粒性狀對鋼材組織和力學(xué)性能的作用機理。為稀土元素在高碳類彈簧鋼中的應(yīng)用提供基礎(chǔ)實驗數(shù)據(jù)，對于開拓鋼鐵材料細晶化方法、調(diào)整鋼鐵品種結(jié)構(gòu)和開發(fā)低成本制造高強韌性鋼材的生產(chǎn)工藝技術(shù)具有重大意義。 通過實驗研究、分析計算和歸納整理，本研究得出以下結(jié)論： （1）在[Ce]含量為0.0046%時，[O]、[S]含量分別降低至0.0017%，0.0012%的水平，，其脫[O]率為81.5%，脫[S]率為76.9%。 （2）當[Ce]含量在0~0.0046%時，鋼材中大尺寸、長條狀的MnS夾雜物變?yōu)?~2μm的橢球形或類球形的MnS與Ce3S4的復(fù)合夾雜物，大尺寸、不規(guī)則的氧化物變?yōu)?~2μm的橢球形（或類球形）氧化物+Ce2O2S（Ce2O3）的復(fù)合夾雜物。 （3）隨[Ce]含量增加，鋼中夾雜物密度增大；但＞2μm的夾雜物數(shù)目顯著減少，可異質(zhì)形核的1~2μm的夾雜物數(shù)目顯著增大。 （4）鋼中加入微量Ce元素后，鋼基體晶粒組織細化，珠光體片層間距變小。在[Ce]含量為0~0.0046%的范圍內(nèi)，珠光體晶粒尺寸由21.65μm減小至13.74μm，鋼基體晶粒度增加1.34倍，珠光體片間距由264nm減小至116.77nm。 （5）隨[Ce]含量增加，65Mn鋼的力學(xué)性能顯著提高。當[Ce]含量為0.0046%時，σs=714.38MPa，σb=864.7MPa、δ=22.75%和Ak=37J，分別比不加Ce時提高4.00%、11.47%、68.52%和45.10%。
[Abstract]:With the rapid development of aerospace, railway, automobile, construction machinery and electronics, the domestic spring steel demand is increasing day by day. Although the production technology and production capacity of spring steel in China are in line with domestic consumption, the import of spring steel of middle and high grade still remains high, which seriously hinders the spring steel industry, the variety structure of iron and steel enterprises and the sustainability of domestic economy. Develop healthily. Spring steel works under special conditions (such as long term load such as tension, compression, bending, torsion and impact). It must not only have stable chemical composition, pure steel, but also fine matrix structure and excellent mechanical properties. According to the current international and domestic production practice of spring steel and the frontier research results of metallurgical theory, this study revolves around the sub-topics of "improving the cleanliness of molten steel, controlling the character of inclusions and the structure of steel, improving the performance of spring steel", etc. Taking the widely used 65Mn steel as the research object, the systematic basic theory research was carried out. In order to improve the microstructure, inclusions and mechanical properties of 65Mn spring steel, the microstructure of spring steel was quantitatively characterized by the theoretical calculation of metallurgical thermodynamics and the study of laboratory scale. Based on the analysis of the variation of inclusions and mechanical properties with trace amount of Ce, the mechanism of inclusion denaturation of Ce content in the molten steel of 0.65%C-0.35%Si-1.20%Mn series during refining and the mechanism of the effect of particle properties of inclusions containing Ce on the microstructure and mechanical properties of steel are discussed. The basic experimental data are provided for the application of rare earth elements in high-carbon spring steels. It is of great significance to develop the method of fine crystallization of iron and steel materials, to adjust the structure of steel varieties and to develop the production technology of high-strength and toughness steels at low cost. Through experimental research, analysis, calculation and induction, the following conclusions are obtained: (1) when [Ce] content is 0.0046, the [O] and [S] contents are reduced to 0.001717 ~ 0.0012%, respectively, with 81.5 [O] removal rate and 76.9% [S] removal rate. (2) when [Ce] content is between 0 and 0.0046, the content of [O] and [S] decrease to 0.0012%, respectively. (2) when the content of [Ce] is 0 ~ 0.0046, the content of [O] and [S] decrease to 0.0017% and 0.0012%, respectively. Large size, long MnS inclusions in steel become ellipsoidal or spherical MnS and Ce3S4 complex inclusions of 1 2 渭 m, large size, Irregular oxides become ellipsoidal (or spherical) oxide Ce2O2S (Ce2O3) complex inclusions with 1 ~ 2 渭 m. (3) the inclusion density increases with the increase of [Ce] content, but the number of inclusions > 2 渭 m decreases significantly. The number of inclusions at 1 ~ 2 渭 m of heterogeneous nucleation increases significantly. (4) the grain structure of the steel matrix is refined and the lamellar spacing of pearlite is reduced with the addition of a small amount of Ce element into the steel. The grain size of pearlite decreases from 21.65 渭 m to 13.74 渭 m, the grain size of steel matrix increases by 1.34 times, and the interlamellar spacing of pearlite decreases from 264nm to 116.77 nm in the range of 0 ~ 0.0046% of [Ce] content. (5) with the increase of [Ce] content, the mechanical properties of the steel increase significantly. When the content of [Ce] was 0.0046, the contents of 蟽 _ (sn) _ (714.38) MPA, 蟽 _ (B) _ (864.7) MPA, 未 ~ (22. 75%) and Ak=37J, were increased by 4.00% and 45.10%, respectively, compared with those without Ce (11.47%, 68.52% and 45.10%, respectively).
【學(xué)位授予單位】：太原理工大學(xué)
【學(xué)位級別】：碩士
【學(xué)位授予年份】：2015
【分類號】：TG142.1

【參考文獻】

相關(guān)期刊論文 前10條

1 祖榮祥;低含碳量彈簧鋼的研究[J];鋼鐵研究學(xué)報;1989年03期

2 徐德祥,尹鍾大;彈簧鋼高強度化及合金元素的作用[J];金屬熱處理;2003年12期

3 張朋彥;高彩茹;朱伏先;;超大熱輸入焊接用EH40鋼的模擬熔合線組織與性能[J];金屬學(xué)報;2012年03期

4 陸志新,唐勁松;寶鋼線材的實物質(zhì)量與改進方向[J];金屬制品;2003年04期

5 申勇;申斌;吳靜;唐武峰;;彈簧鋼的技術(shù)發(fā)展及生產(chǎn)工藝現(xiàn)狀[J];金屬制品;2009年03期

6 王權(quán);陳德富;金自立;;稀土元素對高碳鋼組織及力學(xué)性能的影響[J];金屬熱處理;2012年11期

7 劉延強;王麗君;胡曉軍;周國治;;國內(nèi)外超低氧彈簧鋼生產(chǎn)工藝比較[J];鋼鐵研究學(xué)報;2012年12期

8 梁宇;余凌鋒;梁益龍;;珠光體鋼微觀組織與拉伸性能關(guān)系[J];材料熱處理學(xué)報;2013年07期

9 顧立業(yè);張秉青;;65Mn鋼板開裂原因分析[J];河北冶金;2013年09期

10 吳涌濤;;方大特鋼轉(zhuǎn)爐-精煉-連鑄全工序負能煉鋼實踐剖析[J];河南冶金;2010年04期

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