【摘要】：45鋼因其具有良好的綜合力學(xué)性能而被廣泛應(yīng)用于生物、醫(yī)藥、機(jī)械、化工等眾多領(lǐng)域中。為了進(jìn)一步擴(kuò)大45鋼的應(yīng)用范圍,一般都需要進(jìn)行表面熱處理。離子滲氮處理作為一種應(yīng)用較為廣泛的化學(xué)熱處理技術(shù),具有無(wú)污染、工件變形小和質(zhì)量穩(wěn)定等優(yōu)點(diǎn),能夠顯著提高材料的耐磨性、硬度和耐蝕性等性能。但其不足是,生產(chǎn)周期較長(zhǎng),設(shè)備利用率不高。在此基礎(chǔ)上發(fā)展起來(lái)的離子氮碳共滲技術(shù),生產(chǎn)效率顯著提高。但遺憾的是,離子氮碳共滲處理后,表面容易出現(xiàn)疏松現(xiàn)象。因此,如何克服單一離子滲氮或離子氮碳共滲的不足,有效發(fā)揮離子滲氮與離子氮碳共滲的優(yōu)勢(shì),是材料領(lǐng)域值得深入研究的課題�；诖�,本研究采用空氣、N2和C3H8混合氣體作為氣源,對(duì)45鋼進(jìn)行離子氮碳氧三元共滲處理,研究分析不同空氣流量對(duì)45鋼離子氮碳氧多元共滲的組織與性能的影響;采用離子氮碳共滲與離子滲氮復(fù)合處理方法,研究分析離子復(fù)合處理對(duì)45鋼組織與性能的影響;采用噴砂處理與離子滲氮相結(jié)合的方式,研究分析了噴砂預(yù)處理對(duì)于45鋼離子滲氮組織與性能的影響。分析測(cè)試手段包括:光學(xué)顯微鏡、掃描電鏡、X射線衍射儀、顯微硬度計(jì)、電化學(xué)工作站、磨損試驗(yàn)機(jī)、接觸角測(cè)量?jī)x測(cè)試等。離子氮碳氧三元共滲研究結(jié)果表明,在傳統(tǒng)離子氮碳共滲過(guò)程中添加適量空氣,能顯著提高滲氮效率和改善耐蝕性。在溫度510 ℃、保溫4 h工藝條件下,空氣流量為0.3 L/min時(shí),化合層厚度達(dá)到20.1μm,是傳統(tǒng)離子氮碳共滲化合層厚度的2倍以上。其主要催滲機(jī)理為添加空氣使表層形成了 Fe3O4氧化膜,導(dǎo)致表面接觸角減小和自由能顯著提高。同時(shí),因表面形成的氧化膜有效阻止腐蝕介質(zhì)與基體的接觸,使45鋼耐蝕性得到明顯提高。離子氮碳共滲與離子滲氮復(fù)合處理研究結(jié)果表明,復(fù)合處理可使45鋼獲得比傳統(tǒng)離子滲氮、離子氮碳共滲更快的滲速、更優(yōu)的性能。在相同的處理時(shí)間下,復(fù)合處理滲層厚度比傳統(tǒng)離子滲氮、離子氮碳共滲大幅度增加,有效硬化層比傳統(tǒng)離子滲氮提高約1倍,同時(shí)滲層脆性顯著降低。物相分析表明復(fù)合處理后滲層中的ε相和γ'相的相對(duì)含量發(fā)生了改變,即ε相的相對(duì)含量呈增加趨勢(shì),而γ'相的相對(duì)含量呈減少趨勢(shì)。噴砂處理與離子滲氮復(fù)合處理研究結(jié)果表明,噴砂處理對(duì)45鋼離子滲氮具有明顯的催滲效果。在相同的工藝條件下,最佳的噴砂時(shí)間為15 min,噴砂與離子滲氮復(fù)合處理后化合層厚度比傳統(tǒng)離子滲氮化合層厚度提高約76%;截面顯微硬度比傳統(tǒng)離子離子滲氮顯著提高,硬度最大值提高到799 HVo.05,比傳統(tǒng)離子滲氮的截面硬度提高約125 HVo.05;同時(shí),相比于傳統(tǒng)離子滲氮,噴砂與離子滲氮復(fù)合處理能夠顯著提高耐磨性與耐蝕性,腐蝕速率僅為傳統(tǒng)離子滲氮腐蝕速率的1/3。
[Abstract]:45 steel is widely used in many fields such as biology, medicine, machinery and chemical industry because of its good comprehensive mechanical properties. In order to further expand the application of 45 steel, surface heat treatment is generally required. As a widely used chemical heat treatment technology, ion nitriding has the advantages of no pollution, small workpiece deformation and stable quality. It can significantly improve the wear resistance, hardness and corrosion resistance of the material. But its insufficiency is, the production cycle is longer, the equipment utilization ratio is not high. On this basis, the production efficiency of ion-nitrocarburizing technology has been improved significantly. However, unfortunately, the surface of the surface is prone to appear loose after the treatment of ion nitrogen and carbon. Therefore, how to overcome the shortcomings of single ion nitriding or ion nitrogen carbon co-infiltration, and give full play to the advantages of ion nitriding and ion nitriding is a subject worthy of further study in the field of materials. Based on this, the air N _ 2 and C _ 3H _ 8 mixture gas was used as the gas source to treat 45 steel with ion nitrogen, carbon and oxygen ternary co-infiltration, and the effect of different air flow rate on the microstructure and properties of 45 steel was studied. The effect of ion compound treatment on microstructure and properties of 45 steel was studied by using the method of ion nitriding and ion nitriding, and the method of combining sand blasting and ion nitriding was adopted to study and analyze the effect of ion compound treatment on the microstructure and properties of 45 steel. The effect of sand blast pretreatment on the microstructure and properties of 45 steel ion nitriding was studied. The analytical and testing methods include: optical microscope, scanning electron microscope X-ray diffractometer, microhardness meter, electrochemical workstation, wear tester, contact angle measuring instrument and so on. The results show that adding proper amount of air to the conventional ion nitrocarburizing process can significantly improve the nitriding efficiency and corrosion resistance. Under the conditions of 510 鈩，

本文編號(hào)：2123840