本文選題：失效分析 + 主蒸汽管道　； 參考：《東北石油大學(xué)》2017年碩士論文

【摘要】：隨著國(guó)內(nèi)對(duì)電能需求越來越高,熱電廠對(duì)發(fā)電設(shè)備可靠性的要求也越來越大,因此針對(duì)熱電廠設(shè)備的失效分析就顯得極為重要,而熱電廠中的主蒸汽管道部分作為發(fā)電站的關(guān)鍵部件,因長(zhǎng)期在高溫高壓條件下工作,容易產(chǎn)生裂紋、泄露等現(xiàn)象,嚴(yán)重時(shí)還可能造成人員傷亡,給企業(yè)帶來不可估量的損失,因此如何提高主蒸汽管道的性能顯得十分重要。本設(shè)計(jì)以工程實(shí)例為基礎(chǔ),對(duì)主蒸汽管道的失效模式、影響運(yùn)行壽命的主要因素以及預(yù)防的方法進(jìn)行了系統(tǒng)的分析,為發(fā)電廠主蒸汽管道的性能提供有力的保障,以達(dá)到降低事故頻率、減少損失的目的。納米復(fù)合鍍層是一種重要的表面防護(hù)技術(shù),通過在零件表面制備納米復(fù)合鍍層,可以有效的提高基體的各項(xiàng)性能指標(biāo),增加零件使用壽命,減少生產(chǎn)成本,因此廣泛應(yīng)用于許多工業(yè)領(lǐng)域。合金鍍層中金屬元素含量是決定Ni-Fe合金鍍層性能的一個(gè)重要因素,如何提高鐵元素在復(fù)合鍍層中的含量,己成為當(dāng)前復(fù)合電鍍研究的熱點(diǎn)。本文采用直流電沉積法及脈沖電沉積法在主蒸汽管道材質(zhì)20#鋼表面制備Ni-Fe合金鍍層,并對(duì)其性能進(jìn)行研究得到如下結(jié)論:研究了硫酸鐵濃度、電流密度、攪拌速度、pH值及溫度等參數(shù)對(duì)鍍層中鐵元素含量的影響,優(yōu)選出最佳工藝參數(shù)為:電鍍液中硫酸鐵濃度20 g/L;電流密度1.5 A/dm2;攪拌速度300 rpm;pH值3.5;溫度40℃。利用掃描電鏡、X射線衍射儀對(duì)鍍層的表面形貌、組織結(jié)構(gòu)及元素分布情況進(jìn)行檢測(cè),并探討了Ni-Fe合金鍍層的耐蝕、抗高溫氧化機(jī)理,結(jié)果表明:采用脈沖電沉積法制得的Ni-Fe合金鍍層的耐腐蝕性能強(qiáng)于直流電沉積方法,在相同的腐蝕介質(zhì)中,Ni-Fe合金鍍層的腐蝕電位增大,而腐蝕電流減小。采用脈沖電沉積法制備的Ni-Fe合金鍍層經(jīng)700℃、1.5 h高溫氧化后,其抗高溫氧化性顯著優(yōu)于純鎳鍍層。經(jīng)SEM分析,氧化后純鎳鍍層中鎳原子明顯粗化,表面起伏較大;而Ni-Fe合金鍍層中鎳鐵原子的共沉積抑制了鎳晶粒的長(zhǎng)大,鍍層較平整。用脈沖電沉積法制備的Ni-Fe合金鍍層,由于鐵元素含量高,減小了鎳基質(zhì)氧化時(shí)的實(shí)際接觸面積,因此提高鍍層的抗高溫氧化性。
[Abstract]:With the increasing demand for electric energy in China, the reliability of power generation equipment is becoming more and more important in thermal power plants, so it is very important to analyze the failure of thermal power plant equipment. As the key component of the power station, the main steam pipeline in the thermal power plant is liable to produce cracks and leaks for a long time under the conditions of high temperature and high pressure, which may also cause casualties and bring incalculable losses to the enterprises. Therefore, how to improve the performance of the main steam pipeline is very important. Based on an engineering example, this design systematically analyzes the failure mode of main steam pipeline, the main factors affecting operation life and the preventive methods, which provides a strong guarantee for the performance of main steam pipeline in power plant. In order to reduce the frequency of accidents and reduce losses. Nano-composite coating is an important surface protection technology. By preparing nano-composite coating on the surface of parts, the performance index of matrix can be improved effectively, the service life of parts can be increased, and the production cost can be reduced. Therefore, it is widely used in many industrial fields. The content of metallic elements in alloy coating is an important factor to determine the properties of Ni-Fe alloy coating. How to improve the content of iron in composite coating has become a hot spot in the research of composite electroplating. In this paper, Ni-Fe alloy coating was prepared on the surface of 20# steel by direct current electrodeposition and pulse electrodeposition, and its properties were studied as follows: the concentration of ferric sulfate, current density, current density were studied. The effects of stirring speed, pH value and temperature on the iron content in the coating were studied. The optimum technological parameters were as follows: ferric sulfate concentration 20 g / L in electroplating solution; current density 1.5 A / dm ~ 2; stirring speed 300 rpm ~ (-1) pH value 3.5; temperature 40 鈩，

本文編號(hào)：1846491