發(fā)布時間：2019-01-05 01:51

【摘要】：基于模擬土壤腐蝕模型,建立了土壤孔隙度、含水量、含鹽量以及pH值與腐蝕電流密度間的函數(shù)關(guān)系,分析表明：試樣腐蝕電流密度隨土壤孔隙度的增大而減小,隨土壤含水量的增大先增大后減小,隨土壤含鹽量的增大先增大后趨于穩(wěn)定,隨土壤pH值的降低而增大。為快速評價設(shè)計材料的耐酸性土壤腐蝕能力,建立了硅藻土模擬土壤腐蝕評價方法,模擬土壤單因素試驗(yàn)結(jié)果與腐蝕模型預(yù)測趨勢具有良好的吻合關(guān)系。以此為基礎(chǔ),提出了硅藻土粗細(xì)比4：6、含水量35%,pH值4.5,鹽含量放大5倍的模擬土壤A。模擬土壤與實(shí)際土壤中Q235鋼的腐蝕行為對比研究表明,模擬土壤具有良好的模擬性和加速性,在不改變腐蝕機(jī)理的前提下,最高加速比可達(dá)5倍。 為解決接地網(wǎng)用鋼腐蝕問題,基于多種軟件工具集成計算并初步提出了耐酸性土壤腐蝕接地網(wǎng)用低合金鋼設(shè)計思路。分別采用HSC Chemistry6、 JmatPro、Thermo-Calc軟件分析了鋼中C、Cr、Si口Mn元素對其耐蝕性、導(dǎo)電性、熱熔點(diǎn)的影響規(guī)律：鋼中添加適量的Cr可以有效抑制金屬鐵的陽極溶解,擴(kuò)大材料的鈍化區(qū)；隨C、Cr和Si含量的增加,鋼的電阻率升高,熔點(diǎn)降低;鋼中Mn含量變化對鋼的電阻率和熔點(diǎn)影響不大�；诓牧暇C合性能的集成計算結(jié)果,提出了C含量≤0.1%,Cr含量1.0-2.0%,Si含量≤0.1%,其他元素適量的合金設(shè)計思路,采用高潔凈度冶金工藝煉制了低碳Cr合金化A1鋼和超低碳Cr合金化A2鋼。性能測試結(jié)果表明：A1鋼電阻率較Q235鋼增加了0.07μΩ·m,熔點(diǎn)降低了13℃,其導(dǎo)電性和熱穩(wěn)定性未明顯惡化；A2鋼的電阻率較Q235鋼降低了0.014μΩ·m,熔點(diǎn)增加了15℃,具有良好的導(dǎo)電性和熱穩(wěn)定性。 以模擬土壤A為腐蝕介質(zhì),通過腐蝕失重、SEM、XRD、XPS和電化學(xué)測試等方法,研究了實(shí)驗(yàn)鋼在模擬土壤中的腐蝕行為及腐蝕機(jī)理。結(jié)果表明：高潔凈度冶金工藝降低了鋼中夾雜物等級,減少了點(diǎn)蝕誘發(fā)源數(shù)量；低碳設(shè)計消除了傳統(tǒng)碳鋼中鐵素體與珠光體組織微電池腐蝕；鋼中添加的Cr可以提高鋼的腐蝕電位,降低點(diǎn)蝕發(fā)生敏感性,并隨腐蝕發(fā)展以Fe2CrO4的形態(tài)富集于內(nèi)銹層,促進(jìn)鋼中超細(xì)晶α-(Fe1-x, Crx)OOH的形成,提高了銹層的致密性和保護(hù)能力。腐蝕末期A1和A2鋼的腐蝕速率為0.45mm/a、0.38mm/a,其耐蝕性分別較Q235鋼提高了30%和50%。
[Abstract]:Based on the simulated soil corrosion model, the functional relationship between soil porosity, water content, salt content, pH value and corrosion current density is established. The results show that the corrosion current density decreases with the increase of soil porosity. With the increase of soil moisture content, the soil water content increased first, then decreased, and then stabilized with the increase of soil salt content, and increased with the decrease of soil pH value. In order to quickly evaluate the corrosion resistance of the design materials, a method of simulating soil corrosion by diatomite was established. The results of simulated soil single factor test were in good agreement with the corrosion model prediction trend. On the basis of this, the simulated soil with diatomite aspect ratio of 4: 6, water content of 35% and pH value of 4.5 and salt content of 5 times were proposed. The corrosion behavior of Q235 steel in simulated soil is compared with that in real soil. The results show that the simulated soil has good simulation and acceleration, and the maximum acceleration ratio can reach 5 times without changing the corrosion mechanism. In order to solve the problem of steel corrosion in grounding grid, the design idea of low alloy steel for grounding grid for acid resistant soil corrosion is put forward based on the integrated calculation of various software tools. The effects of Mn elements on corrosion resistance, electrical conductivity and hot melting point were analyzed by HSC Chemistry6, JmatPro,Thermo-Calc software. The addition of appropriate amount of Cr in steel can effectively inhibit the anodic dissolution of iron. Expanding the passivation zone of the material; With the increase of Cr and Si content, the resistivity of steel increases and the melting point decreases, and the change of Mn content in steel has little effect on the resistivity and melting point of steel. Based on the results of the integrated calculation of the comprehensive properties of the materials, the design idea of alloy with C content 鈮，

本文編號：2401102