本文關(guān)鍵詞：強(qiáng)流脈沖電子束處理50BA及30SiMn2MoVA高強(qiáng)鋼的顯微組織及性能研究　出處：《重慶理工大學(xué)》2015年碩士論文　論文類型：學(xué)位論文

  更多相關(guān)文章： 50BA高強(qiáng)鋼 30SiMn2MoVA高強(qiáng)鋼 強(qiáng)流脈沖電子束 表面改性

【摘要】：高強(qiáng)鋼(High Strength Steel)具有優(yōu)良的綜合力學(xué)性能,廣泛應(yīng)用于軍事、民用領(lǐng)域。隨著零件的服役環(huán)境變得復(fù)雜化、多樣化、惡劣化,對材料的性能提出了更高的要求。目前,傳統(tǒng)化學(xué)熱處理方法存在著能量利用率低、生產(chǎn)效率低、工件變形量大、污染環(huán)境等缺點(diǎn),表面涂層技術(shù)又存在著結(jié)合力差的缺點(diǎn),而強(qiáng)流脈沖電子束(HCPEB)作為一種新型的高能、高效的表面改性技術(shù)以其自身獨(dú)特的優(yōu)勢,規(guī)避了傳統(tǒng)表面改性技術(shù)的缺陷,能夠達(dá)到提高零件表面強(qiáng)度、耐磨性和耐蝕性能的目的。本論文分別以50BA和30SiMn2MoVA高強(qiáng)鋼為基材,利用強(qiáng)流脈沖電子束設(shè)備以不同的脈沖次數(shù)對試樣表面進(jìn)行重熔處理,主要研究了改性前后試樣的表截面顯微形貌、微觀組織結(jié)構(gòu)的變化規(guī)律以及耐磨性和耐蝕性等力學(xué)性能的變化情況。研究結(jié)果表明:(1)經(jīng)HCPEB處理后,試樣表面經(jīng)過熔體噴發(fā),產(chǎn)生了火山坑狀的“熔坑”。50BA高強(qiáng)鋼試樣表面的“熔坑”呈彌散分布,30SiMn2MoVA高強(qiáng)鋼試樣表面的“熔坑”呈網(wǎng)狀結(jié)構(gòu),隨著脈沖次數(shù)的增加,熔坑的數(shù)量逐漸減少,試樣表面微區(qū)逐漸變得平滑,50BA高強(qiáng)鋼試樣表面熔坑尺寸先增大后變小,30SiMn2MoVA高強(qiáng)鋼試樣表面熔坑尺寸變小,網(wǎng)狀結(jié)構(gòu)逐漸消失,熔坑逐漸呈現(xiàn)出獨(dú)立分布狀態(tài)。(2)50BA和30SiMn2MoVA高強(qiáng)鋼試樣表面都發(fā)生了相變,產(chǎn)生了馬氏體和殘余奧氏體,隨著脈沖次數(shù)的增加,馬氏體的含量相對減少,殘余奧氏體的含量相對增加。快速加熱與凝固使試樣表層晶粒細(xì)化,第二相顆粒尺寸變小,分布更為均勻。(3)經(jīng)HCPEB處理后,試樣表面顯微硬度得到提高,其中50BA高強(qiáng)鋼經(jīng)50次脈沖處理后,表面硬度最大,相比于原始試樣提高了20.9%;30SiMn2MoVA高強(qiáng)鋼經(jīng)30次脈沖處理后,表面硬度相比于原始試樣提高了39.6%。試樣表面組織由馬氏體和殘余奧氏體組成,這種軟硬復(fù)合相的存在以及晶粒細(xì)化都有助于提高試樣表面的耐磨性。試樣磨損量隨脈沖次數(shù)的增加而降低,相對耐磨性至少提高1倍,其中30和50次脈沖處理后試樣的相對耐性相對于原始試樣都提高了2倍。在耐蝕性方面,隨著脈沖轟擊次數(shù)的增加,試樣表面腐蝕電流密度逐漸降低,腐蝕電位逐漸升高,使腐蝕速率降低,腐蝕傾向性減小,其中50BA高強(qiáng)鋼試樣表面經(jīng)50次脈沖處理后試樣表面的耐蝕性能最好,腐蝕電流密度降低了43.5%,30SiMn2MoVA高強(qiáng)鋼試樣表面經(jīng)30次脈沖處理后試樣表面的耐蝕性能最好,腐蝕電流密度降低了48.8%。
[Abstract]:High strength steel Strength steel has excellent comprehensive mechanical properties and is widely used in military and civil fields. With the service environment of parts becomes more and more complicated and diversified. At present, the traditional chemical heat treatment methods have the disadvantages of low energy utilization, low production efficiency, large deformation of workpiece, pollution of environment and so on. As a new type of high energy and high efficiency surface modification technology HCPEB has its own unique advantages. Avoiding the defects of the traditional surface modification technology, it can improve the surface strength, wear resistance and corrosion resistance of the parts. In this paper, 50BA and 30SiMn2MoVA high strength steel are used as the substrates, respectively. High current pulsed electron beam equipment was used to remelt the surface of the sample with different pulse times. The microstructure of the surface section of the sample before and after modification was studied. The change of microstructure, wear resistance and corrosion resistance, the results show that after HCPEB treatment, the surface of the sample is ejected by melt. The "melting pit" on the surface of the high-strength steel sample with volcanic crater shape. 50BA is distributed diffusely. The "melting pit" of the specimen surface of 30SiMn2MoVA high strength steel has a network structure. With the increase of pulse number, the number of melting pits decreases gradually, and the surface microzone becomes smooth and the surface size of 50BA high strength steel first increases and then becomes smaller. The size of the melting pit on the surface of 30SiMn2MoVA high strength steel becomes smaller and the mesh structure gradually disappears. The melting pits gradually show an independent distribution state. Both the surface of the specimens of 30SiMn2MoVA and 30SiMn2MoVA have been transformed, resulting in martensite and retained austenite, with the increase of pulse times. The content of martensite decreases and the content of residual austenite increases. The grain size of the surface layer of the sample is refined and the size of the second phase grain is smaller by rapid heating and solidification. After HCPEB treatment, the surface microhardness of 50BA high strength steel was increased, and the surface hardness of 50BA high strength steel was the largest after 50 pulse treatment. Compared with the original sample, 20.9% was increased. After 30 pulse treatment, the surface hardness of 30SiMn2MoVA high strength steel is 39.6 higher than that of the original sample. The surface microstructure of 30SiMn2MoVA steel is composed of martensite and retained austenite. The existence of the soft and hard composite phase and grain refinement can improve the wear resistance of the sample surface. The wear rate of the sample decreases with the increase of pulse number, and the relative wear resistance increases by at least one time. The relative resistance of the samples after 30 and 50 pulse treatments was increased by 2 times compared with the original samples. In terms of corrosion resistance, the corrosion current density of the samples gradually decreased with the increase of pulse bombardment times. The corrosion potential increases gradually, the corrosion rate decreases and the corrosion tendency decreases. The surface of 50BA high strength steel is treated with 50 pulses and the corrosion resistance is the best. The corrosion current density is reduced by 43.5% and the corrosion resistance of the sample surface treated with 30 pulses is the best, and the corrosion current density is reduced by 48.8%.
【學(xué)位授予單位】：重慶理工大學(xué)
【學(xué)位級別】：碩士
【學(xué)位授予年份】：2015
【分類號】：TG174.4

【參考文獻(xiàn)】

相關(guān)期刊論文 前2條

1 徐濱士;譚俊;陳建敏;;表面工程領(lǐng)域科學(xué)技術(shù)發(fā)展[J];中國表面工程;2011年02期

2 趙鐵鈞;田小梅;高波;涂贛峰;;電子束表面處理的研究進(jìn)展[J];材料導(dǎo)報(bào);2009年05期

，

本文編號：1427356