本文選題：高鋼級油套管 + 硫化物應力開裂　； 參考：《西安石油大學》2017年碩士論文

【摘要】：本文在高鋼級油套管用鋼理化性能測試分析的基礎上,利用NACE TM 0177-2013標準A法、四點彎曲法和雙懸臂梁法分析P110、C110和125S三種高鋼級油套管材料在硫化氫腐蝕環(huán)境下的應力開裂規(guī)律;運用Devanathan-Stachurski雙電解池技術,研究高鋼級油套管用鋼的氫滲透行為及影響因素,探討其SSC抗力與氫通量、氫含量之間的關系。結果表明:與P110鋼相比,C110和125S鋼的組織更加細小,夾雜物呈球形,晶粒內(nèi)有較高密度的位錯和彌散分布的碳化物;相比于P110、125S鋼,C110鋼硬度最低,沖擊功最高,通過了NACE TM 0177-2013標準規(guī)定的抗SSC性能檢測,具有良好的抗硫化物應力開裂性能。隨著加載應力水平和陰極保護電位的升高,高強度油套管用鋼的SSC敏感性增強;但隨著溫度升高,高強度油套管用鋼的SSC敏感性明顯降低,其在高溫環(huán)境下的KISSC值更高,抗SSC性能增強。氫滲透行為研究的結果表明,在5%wt NaCl溶液和NACE TM 0177-2013標準A溶液兩種溶液體系中,隨著H_2S分壓的增大、溶液pH值的降低和外加陰極電位的增大,高強度油套管用鋼的穩(wěn)態(tài)氫滲透電流密度增大,次表面氫濃度升高。高強度油套管用鋼的次表面氫濃度和可擴散氫含量隨溫度升高、腐蝕時間的延長呈先上升后降低的趨勢,并且其可擴散氫含量在腐蝕168 h后(24±3℃)達到最大值。在腐蝕環(huán)境一致條件下,具有典型Cr-Mo鋼成分設計的C110油套管具有良好的抗SSC性能;成分設計與C110基本相同的125S油套管的強度增大,顯微組織結構進一步細化,位錯、晶界、亞晶界等亞結構數(shù)量明顯增多,在金屬內(nèi)部存在的“氫陷阱”增多,導致其內(nèi)部可擴散氫含量及次表面氫濃度增大,SSC敏感性增強。
[Abstract]:Based on the analysis of physical and chemical properties of high grade oil casing steel, the stress cracking law of three kinds of high steel oil casing materials P110C110 and 125S under hydrogen sulfide corrosion environment is analyzed by NACE TM0177-2013 standard A method, four point bending method and double cantilever beam method. The hydrogen permeation behavior of high grade oil casing steel and its influencing factors were studied by means of Devanathan-Stachurski double electrolytic cell technology. The relationship between SSC resistance and hydrogen flux and hydrogen content was discussed. The results show that the microstructure of C110 and 125S steels is smaller than that of P110 steel, the inclusions are spherical, there are high density dislocations and dispersed carbides in the grains, the hardness is the lowest and the impact work is the highest in comparison with P110125S steels. The NACE TM 0177-2013 standard has passed the test of SSC resistance, and has good resistance to sulfide stress cracking. With the increase of loading stress level and cathodic protection potential, the SSC sensitivity of high strength oil casing steel increases, but with the increase of temperature, the SSC sensitivity of high strength oil casing steel decreases obviously, and the KISSC value of high strength oil casing steel increases at high temperature. Enhanced anti-SSC performance. The results of hydrogen permeation behavior show that in 5%wt NaCl solution and NACE TM0177-2013 standard A solution system, with the increase of H _ 2S partial pressure, the pH value of the solution decreases and the applied cathode potential increases. The steady-state hydrogen permeation current density of high strength oil casing steel increases, and the hydrogen concentration of subsurface increases. The subsurface hydrogen concentration and diffusible hydrogen content of high strength oil casing steel increased with the increase of temperature, and the corrosion time increased first and then decreased, and the diffusible hydrogen content reached its maximum value at 24 鹵3 鈩，

本文編號：1903371