本文選題：2205雙相不銹鋼　切入點：電化學　出處：《江蘇科技大學》2015年碩士論文

【摘要】：2205雙相不銹鋼是一種由鐵素體和奧氏體兩相構成的第二代新型雙相不銹鋼。其強度高,且耐蝕性能好,是石油、化工、冶金等行業(yè)應用非常廣泛的材料。本課題以2205雙相不銹鋼棒材為研究對象,采用金相觀測法、極化曲線、電化學阻抗譜技術、氫滲透曲線和慢應變速率拉伸結(jié)合掃描電鏡,研究了微觀組織和鉬酸鹽對2205雙相不銹鋼耐蝕性能以及氫脆的影響,結(jié)果表明:當固溶處理溫度從950℃升高至1150℃時,σ相逐漸溶解,并且基體中的鐵素體含量逐漸升高,奧氏體含量逐漸降低;點蝕易發(fā)生于鐵素體和奧氏體晶界處,并且容易向鐵素體相內(nèi)擴展。氫滲透曲線結(jié)合慢應變速率拉伸實驗結(jié)果表明:H原子在2205雙相不銹鋼中的擴散系數(shù)與雙相不銹鋼中的鐵素體含量成正比,當鐵素體和奧氏體相含量較平均時,材料的氫脆敏感性顯著降低,耐點蝕性能提高。通過改變鉬酸根離子濃度及溶液溫度,研究2205雙相不銹鋼不銹鋼極化曲線,電化學阻抗,氫滲透曲線及慢應變速率拉伸的變化,分析材料腐蝕性能的變化規(guī)律,并結(jié)合微觀腐蝕形貌和斷口形貌的變化,明確鉬酸鹽對腐蝕性能的影響:鉬酸根離子提高雙相不銹鋼的耐點蝕性能以及降低材料氫脆敏感性,且MoO42-和Cl-在不銹鋼表面存在競爭吸附,MoO42-在合金表面形成一層阻礙Cl-吸附的鹽離子阻擋膜;MoO42-或其反應產(chǎn)物能夠阻礙H原子在雙相不銹鋼表面吸附,減小氫的擴散速率,降低雙相不銹鋼的氫脆敏感性,提高材料的耐應力腐蝕性能。該工作對2205雙相不銹鋼在石油天然氣、化工等行業(yè)的應用奠定了基礎,對提高2205雙相不銹鋼的使用性能具有一定的實際指導意義。
[Abstract]:2205 duplex stainless steel is a new type of second generation duplex stainless steel composed of ferrite and austenite.It has high strength and good corrosion resistance. It is widely used in petroleum, chemical, metallurgical and other industries.In this paper, 2205 duplex stainless steel bar was studied. Metallographic observation, polarization curve, electrochemical impedance spectroscopy, hydrogen permeation curve and slow strain rate tensile combined with scanning electron microscope were used.The effects of microstructures and molybdate on corrosion resistance and hydrogen embrittlement of 2205 duplex stainless steel were studied. The results showed that the 蟽 phase dissolved gradually and the ferrite content in the matrix increased gradually when the solution temperature increased from 950 鈩，

本文編號：1717823