【摘要】：本文采用調(diào)質(zhì)處理+低溫氣體多元共滲+電鍍鋅復(fù)合處理工藝,不僅使45鋼和20MnTiB合金鋼的力學(xué)性能得到了提升,還顯著提高了其耐腐蝕性能和耐疲勞性能。該工藝主要用于高強(qiáng)螺栓的表面處理,試樣表面美觀,具有較高的硬度、抗拉強(qiáng)度以及良好的沖擊韌性,同時(shí)還有很好的防腐性能和較高的疲勞強(qiáng)度,該新型復(fù)合處理工藝具有重要的工業(yè)價(jià)值。分別對(duì)8.8級(jí)高強(qiáng)螺栓鋼(調(diào)質(zhì)態(tài)45鋼)和10.9級(jí)高強(qiáng)螺栓鋼(調(diào)質(zhì)態(tài)20MnTiB鋼)進(jìn)行三種不同的表面處理(多元共滲、鍍鋅處理、復(fù)合處理),利用激光共聚焦、超景深三維顯微鏡、X射線衍射(XRD)等分析測(cè)試技術(shù),對(duì)不同表面處理后的兩種高強(qiáng)螺栓鋼試樣進(jìn)行了顯微組織和宏觀形貌觀察,分析了其表層的物相組成,測(cè)定了鍍鋅層和多元滲層的結(jié)合強(qiáng)度及其常規(guī)力學(xué)性能,采用中性鹽霧腐蝕試驗(yàn)和高頻疲勞試驗(yàn)分析評(píng)價(jià)了其防腐性能和疲勞性能,通過(guò)掃描電鏡(SEM)分析了其拉伸和疲勞斷裂機(jī)理。試驗(yàn)結(jié)果表明:45鋼復(fù)合處理后,晶粒更加細(xì)小,滲鍍層組織均勻致密,鍍鋅層與多元滲層的結(jié)合強(qiáng)度良好,滲鍍層厚度為50μm;經(jīng)XRD分析得出樣品表面存在有Zn(鍍鋅層)、氮化物(Fe3N)、碳化物(Fe3C)和氧化物(Fe3O4),其中碳化物和氮化物起到彌散強(qiáng)化的作用;滲鍍層的顯微硬度最大可達(dá)到636HV0.025左右,大約是基體顯微硬度的兩倍;抗拉強(qiáng)度為830MPa,提高到原材的1倍;沖擊吸收功為32.9J,是原材的78%;其抗鹽霧時(shí)間845h后保護(hù)等級(jí)達(dá)到9級(jí)(觀察面開始出現(xiàn)少許點(diǎn)狀紅銹),防腐時(shí)間達(dá)到了原材的170倍左右;缺口試樣的條件疲勞極限為369MPa,較原材的缺口試樣有所提升。20MnTiB合金鋼復(fù)合處理后,由于合金元素的影響,其滲鍍層厚度僅僅28μm;滲鍍層的物相主要有Zn(鍍鋅層)、氮化物(Fe3N)、氧化物(Fe203)和碳化物(Fe3C)等。滲鍍層顯微硬度最高可達(dá)到756HV0.025,抗拉強(qiáng)度可達(dá)到904MPa,提高到原材的1.1倍,沖擊吸收功為166.5J,表現(xiàn)為較好的沖擊韌性,但較調(diào)質(zhì)態(tài)有所下降,其抗鹽霧時(shí)間846h后保護(hù)等級(jí)達(dá)到9級(jí),得到了大幅度的提高,缺口試樣的條件疲勞極限為382MPa,較原材的缺口試樣有所提高。
[Abstract]:In this paper, the mechanical properties of 45 steel and 20MnTiB alloy steel have been improved, and the corrosion resistance and fatigue resistance of 45 steel and 20MnTiB alloy steel have also been improved. The process is mainly used for the surface treatment of high strength bolts. The surface of the sample is beautiful, with high hardness, tensile strength and good impact toughness, at the same time, it also has good anticorrosive property and high fatigue strength. The new composite treatment process has important industrial value. Three different surface treatments (multicomponent co-infiltration, galvanizing treatment and composite treatment) were carried out on 8.8-grade high strength bolt steel (quenched and tempered 45 steel) and 10.9 grade high strength bolt steel (quenched and tempered 20MnTiB steel). The microstructure and macroscopic morphology of two kinds of high strength bolted steel specimens after different surface treatment were observed by means of X ray diffraction (XRD) and other techniques. The phase composition of the surface layer was analyzed. The bonding strength and conventional mechanical properties of galvanized and multicomponent coating were measured. The corrosion resistance and fatigue performance of zinc coating were evaluated by neutral salt spray corrosion test and high frequency fatigue test. The tensile and fatigue fracture mechanisms were analyzed by scanning electron microscope (SEM). The results show that the grain size is finer, the microstructure of the coating is uniform and compact, and the bonding strength between the galvanizing layer and the multicomponent layer is good. The thickness of percolation coating is 50 渭 m. XRD analysis shows that there are Zn (galvanized layer), nitride (Fe3N), carbide (Fe3C) and oxide (Fe3O4) on the surface of the sample, in which carbides and nitrides play the role of dispersion strengthening, and the microhardness of the coating can reach about 636HV0.025. The tensile strength is 830MPa, which is twice as high as that of the original material. The impact absorption energy is 32.9J, which is 78% of the original material, and the protective grade is 9 after the salt spray resistance time is 845h (the observed surface begins to appear a little spot red rust), and the anticorrosion time is about 170 times of the original material. The fatigue limit of the notched specimen is 369MPa. Compared with the notched specimen of the original material, the fatigue limit of the notched specimen is increased. 20MnTiB alloy steel after composite treatment, due to the effect of alloying elements, The coating thickness is only 28 渭 m. The main phases of the coating are Zn (galvanizing layer), nitride (Fe3N), oxide (Fe203) and carbides (Fe3C). The microhardness and tensile strength of the permeable coating can reach 756HV0.025 and 904MPa, which can be increased to 1.1 times of the original material, and the impact absorption energy is 166.5J. the impact toughness of the coating is better, but it is lower than that of the tempering state. The protective grade of the coating is 9 after the salt spray resistance time is 846 hours. The fatigue limit of the notched specimen is 382 MPA, which is higher than that of the original notched specimen.
【學(xué)位授予單位】：西南交通大學(xué)
【學(xué)位級(jí)別】：碩士
【學(xué)位授予年份】：2017
【分類號(hào)】：TG142.1;TG178

【參考文獻(xiàn)】

相關(guān)期刊論文 前10條

1 楊旭;王亞兵;雷宏剛;;不同應(yīng)力幅下高強(qiáng)螺栓的疲勞破壞特征研究[J];太原理工大學(xué)學(xué)報(bào);2016年02期

2 ZHAO Lihui;ZHENG Songlin;FENG Jinzhi;;Fatigue Life Prediction under Service Load Considering Strengthening Effect of Loads below Fatigue Limit[J];Chinese Journal of Mechanical Engineering;2014年06期

3 張錦秋;安茂忠;李崇幸;楊培霞;;電鍍鋅層無(wú)鉻鈍化工藝的研究[J];電鍍與環(huán)保;2013年05期

4 唐云峰;車漢生;;常用鹽霧試驗(yàn)標(biāo)準(zhǔn)及相關(guān)結(jié)果評(píng)價(jià)[J];環(huán)境技術(shù);2012年06期

5 薛崤;陳超;秦亮;崔國(guó)棟;;表面強(qiáng)化處理工藝對(duì)20CrMnTi鋼性能的影響[J];機(jī)車車輛工藝;2011年06期

6 劉揚(yáng)泰;陳侃;崔本全;吳文君;黃玉萍;;精密零件的氣體多元共滲[J];金屬熱處理;2011年04期

7 王萌;石永久;王元清;;高強(qiáng)度螺栓連接抗剪性能研究[J];建筑結(jié)構(gòu)學(xué)報(bào);2011年03期

8 崔國(guó)棟;鄭周;朱鵬霄;屈艾;易超絕;;多元共滲處理對(duì)30Cr2MoV鋼性能的影響[J];實(shí)驗(yàn)科學(xué)與技術(shù);2010年05期

9 劉雷;李培耀;;高強(qiáng)度螺栓材料的研究現(xiàn)狀與趨勢(shì)[J];上海工程技術(shù)大學(xué)學(xué)報(bào);2010年02期

10 李會(huì)謙;許跟國(guó);馬江虹;冀國(guó)娟;王夢(mèng)雨;;熱浸鍍技術(shù)及其應(yīng)用[J];有色金屬(冶煉部分);2008年S1期

相關(guān)博士學(xué)位論文 前2條

1 翟建明;金屬材料經(jīng)硫化氫腐蝕后的疲勞可靠性研究[D];北京工業(yè)大學(xué);2013年

2 王弘;40Cr、50車軸鋼超高周疲勞性能研究及疲勞斷裂機(jī)理探討[D];西南交通大學(xué);2004年

相關(guān)碩士學(xué)位論文 前10條

1 何昭民;緊固件表面電鍍鉻工藝及性能研究[D];沈陽(yáng)工業(yè)大學(xué);2016年

2 鄭少華;表面復(fù)合處理工藝對(duì)合金鋼緊固件力學(xué)性能和抗腐蝕性能的影響[D];西南交通大學(xué);2014年

3 鄒靖;鋼結(jié)構(gòu)高強(qiáng)度螺栓連接副力學(xué)行為的研究[D];中南大學(xué);2014年

4 傅俊磊;鋼鐵表面鋅覆蓋層顯微組織檢驗(yàn)技術(shù)的研究[D];浙江大學(xué);2013年

5 歐陽(yáng)卿;高強(qiáng)螺栓受力及疲勞性能研究[D];湖南大學(xué);2013年

6 羅雪香;摻雜合金元素多元共滲層耐蝕性能及阻抗譜研究[D];西南交通大學(xué);2012年

7 饒小松;QPQ與鍍鋅復(fù)合處理對(duì)風(fēng)電高強(qiáng)度緊固件力學(xué)性能和抗腐性能的影響[D];西華大學(xué);2011年

8 鄭周;控制表面顏色的多元共滲復(fù)合處理工藝及組織性能研究[D];西南交通大學(xué);2011年

9 高培;摻雜鋁元素的多元共滲復(fù)合處理工藝及其防腐蝕性能的研究[D];西南交通大學(xué);2011年

10 李海升;多元共滲—鎳磷復(fù)合處理工藝及復(fù)合層功能特性研究[D];西南交通大學(xué);2009年

，

本文編號(hào)：2247595