-
摘要: 針對某石油套管鋼管壁內缺陷，采用掃描電鏡?能譜儀（SEM-EDS）分析，并結合FactSage8.0軟件計算進行研究，結果表明缺陷縱向面主要由淺條紋及深條紋組成，淺條紋處存在大量MgO·Al2O3夾雜物，深條紋處有大量的Al2O3、MgO·Al2O3、CaO·Al2O3·SiO2等夾雜物聚集在一起。缺陷橫截面上的夾雜物主要為CaO·Al2O3·SiO2、CaO·Al2O3·MgO和CaO·Al2O3·MgO·SiO2 3類。推測鋼管壁內缺陷形成機理主要為：①大包鋼水在澆注末期鋼水卷帶鋼包渣進入中間包鋼水中，該渣滴隨后吸附鋼中高Al2O3含量的微細xAl2O3·yCaO或Al2O3夾雜物，導致渣滴中的Al2O3含量升高；②大包鋼水在真空脫氣（VD）精煉過程大Ar氣攪拌下卷入了鋼包渣，該渣滴隨后吸附鋼中的微細Al2O3夾雜物，導致渣滴中的Al2O3含量升高；以上兩種形式形成的渣滴在凝固冷卻過程中，轉變為CaO·Al2O3·SiO2, CaO·Al2O3·MgO，CaO·Al2O3·SiO2·MgO 3種類型的夾雜物。圓管坯在穿孔變形過程中，在縱向拉應力和橫向切應力作用下，使卷入的大型渣滴沿縱向及橫截面延伸擴展，最終形成鋼管壁內的缺陷。Abstract: In this study, the defects in the wall of petroleum casing steel pipe were investigated. The morphology and composition of inclusions in the defects of the steel pipe were analyzed using scanning electron microscopy–energy-dispersive X-ray spectroscopy. The thermodynamic calculation of the Ca?Al equilibrium phase diagram of molten steel in tundish and the changes of the ladle slag phase composition with cooling temperature was performed using FactSage8.0. The results show that the longitudinal surface of the defect is mainly composed of shallow and deep stripes. A large number of MgO·Al2O3 inclusions containing a small amount of Mn is detected at shallow stripes, and a large number of inclusions, such as Al2O3, MgO·Al2O3, and CaO·Al2O3·SiO2 are detected at deep stripes. The three main types of inclusions in the cross-section of the defect zone are CaO·Al2O3·SiO2, CaO·Al2O3·MgO, and CaO·Al2O3·MgO·SiO2. According to the analysis results of inclusions in the cross-section and the calculation results of the phase transformation of slag droplets during solidification and cooling, the formation mechanism of the defects in the wall of steel pipe can be speculated as follows: (1) At the end of pouring, the ladle slag in molten steel in the ladle enters the tundish. Further, the slag droplets adsorb the fine xAl2O3·yCaO or Al2O3 inclusions with high Al2O3 content in molten steel, increasing the Al2O3 and CaO contents in the slag droplets. (2) Ladle slag in molten steel is subjected to strong stirring in Ar gas in the vacuum degassing (VD) refining process. Moreover, the slag droplets adsorb the fine Al2O3 inclusions in molten steel, increasing the Al2O3 content in the slag droplets. During solidification and cooling, the slag droplets formed in the two aforementioned forms of inclusions are transformed into three types of inclusions: CaO·Al2O3·SiO2, CaO·Al2O3·MgO, and CaO·Al2O3·SiO2·MgO. In the process of round billet piercing deformation, under the action of longitudinal tensile stress and transverse shear stress, the large slag droplets involved extend along the longitudinal cross-section and finally form defects in the wall of the steel pipe.
-
Key words:
- steel pipe /
- defect /
- phase transformation of slag /
- phase diagram /
- ladle slag
-
圖 1 樣品缺陷及缺陷處橫截面取樣示意圖
Figure 1. Schematic diagram of the sample defects and cross-sectional sampling of the defect zone
圖 2 樣品淺條紋缺陷處典型夾雜物形貌及成分面掃圖
Figure 2. Morphology and scanned maps of typical inclusions at the shallow stripe defect zone
圖 3 樣品深條紋缺陷處典型夾雜物形貌及面掃圖
Figure 3. Morphology and scanned maps of typical inclusions at the deep stripe defect zone
圖 4 各橫截面觀察單元取樣示意圖
Figure 4. Sampling diagrams of observation units on each cross-section
圖 5 各橫截面觀察單元及各橫截面總面積的變化
Figure 5. Changes of the area of each observation unit and the total area of each cross-section
圖 6 各橫截面處夾雜物組成在CaO?Al2O3?SiO2相圖中的分布(1600 °C)
Figure 6. Distribution of the inclusion composition in the CaO?Al2O3?SiO2 phase diagram at each cross-section (1600 ℃)
圖 7 各橫截面處夾雜物組成在CaO?Al2O3?MgO相圖中的分布 (1600 °C)
Figure 7. Distribution of the inclusion composition in the CaO?Al2O3?MgO phase diagram at each cross-section (1600 ℃)
圖 8 各橫截面上CaO·Al2O3·MgO·SiO2類夾雜物各組成平均成分及堿度R的變化
Figure 8. Changes of the average composition and basicity R of CaO·Al2O3·MgO·SiO2 inclusions on each cross-section
圖 9 橫截面缺陷處典型夾雜物的形貌與面掃描圖. (a~c) 形貌圖; (d) 面掃描圖
Figure 9. Morphology and scanned maps of typical inclusions at the cross-section of the defect zone: (a–c) morphology images; (d) scanned map images
圖 10 依據中間包鋼液成分的Mg?Al?Ca?O?S?Si夾雜物的平衡隨Ca和Al質量分數的變化(1600 °C)
Figure 10. Calculated equilibrium phase diagram of Mg?Al?Ca?O?S?Si inclusions in molten steel in tundish at different Ca and Al contents (1600 °C)
圖 11 卷入鋼包渣在凝固冷卻過程中的各相成分變化
Figure 11. Transformation of the ladle slag entrainment during solidification and cooling
圖 12 缺陷中夾雜物形成機理：第一種方式
Figure 12. Formation mechanism of inclusions at the defect zone: the first way
圖 13 缺陷中夾雜物形成機理：第二種方式
Figure 13. Formation mechanism of inclusions at the defect zone: the second way
表 1 鋼包渣的主要成分(質量分數)
Table 1. Composition of ladle slag
% CaO SiO2 Al2O3 MgO T.Fe 59.9 12.0 21.6 4.93 0.48 
下載: 導出CSV
表 2 中間包鋼水成分(質量分數)
Table 2. Composition of molten steel in tundish
% C Si Mn P S Cr Mo Mg Als Ca O N Fe 0.29 0.26 0.45 0.009 0.0018 0.547 0.868 0.0004 0.022 0.0020 0.0015 0.0054 97.543
下載: 導出CSV
中文字幕在线观看表 3 缺陷處典型夾雜物組成(質量分數)
Table 3. Composition of typical inclusions at the defect zone
% No. O Mg Al Si Ca Mn 1 41.6 15.5 39.4 0 0 2.03 2 43.6 11.9 42.1 0 2.40 0 3 44.0 0 36.6 5.99 13.4 0
下載: 導出CSV
-
參考文獻
[1] Feng Q, Yu H, Liu B, et al. Influence of continuous casting billet surface defects on continuous rolling steel pipe surface quality. Phys Test Chem Anal (Part A Phys Test) , 2015, 51(10): 679馮慶, 于輝, 劉波, 等. 連鑄坯表面缺陷對連軋鋼管表面質量的影響. 理化檢驗(物理分冊), 2015, 51(10):679 [2] Deng M M, Peng Q C, Xiao Y Q, et al. Analysis on mottled spots defect of internal surface of ?185 mm×13 mm cold-drawn tube of steel 25Mn. Special Steel, 2017, 38(6): 23 doi: 10.3969/j.issn.1003-8620.2017.06.006鄧明明, 彭其春, 肖云清, 等. 25Mn鋼?185 mm×13 mm冷拔管內表面麻點狀缺陷的分析和控制工藝. 特殊鋼, 2017, 38(6):23 doi: 10.3969/j.issn.1003-8620.2017.06.006 [3] Wang H, Zhao J M. Analysis on spot defects of E355 steel cold drawing cylinder tube. Phys Test Chem Anal (Part A Phys Test) , 2020, 56(3): 57王樺, 趙健明. 某E355鋼冷拔油缸管點狀缺陷分析. 理化檢驗(物理分冊), 2020, 56(3):57 [4] Lang Y M, Nie X H, Wang G F, et al. Cracking reason analysis of 20 steel seamless pipe. Hot Work Technol, 2016, 45(10): 257郎一鳴, 聶向暉, 王高峰, 等. 20鋼無縫管開裂原因分析. 熱加工工藝, 2016, 45(10):257 [5] Chang Z T, Wei Z S, Li Z, et al. Analysis and improvement of quality defects in low-carbon steel continuously casting billets. Foundry Technol, 2017, 38(11): 2717常鎮韜, 魏占山, 李壯, 等. 低碳鋼連鑄坯質量缺陷分析及改進. 鑄造技術, 2017, 38(11):2717 [6] Qin X H, Qi X F, Zhang X H. Cause analysis and improvement measures of scaly defects on inner surface of 37Mn5 steel pipe. China Metall, 2020, 30(8): 42秦緒華, 齊曉峰, 張秀華. 37Mn5鋼管內壁鱗片狀缺陷原因分析及改進措施. 中國冶金, 2020, 30(8):42 [7] Zhou L X, Li B, Chen F Y, et al. Fracture analysis of tube 30CrMnSiA. Phys Exam Test, 2012, 30(4): 43周立新, 李波, 陳方玉, 等. 30CrMnSiA管材斷裂原因分析. 物理測試, 2012, 30(4):43 [8] Li H G, Chen T M, Chen L, et al. Analyze and control for peeling defects on the internal surface of JS25Mn steel tube. Iron Steel Vanadium Titanium, 2016, 37(5): 153 doi: 10.7513/j.issn.1004-7638.2016.05.026李紅光, 陳天明, 陳亮, 等. JS25Mn鋼管內表面起皮缺陷分析與控制. 鋼鐵釩鈦, 2016, 37(5):153 doi: 10.7513/j.issn.1004-7638.2016.05.026 [9] Ma Y X, Wang K, Men Z X, et al. Analysis on crack defects in Q345D steel billet. Foundry Technol, 2016, 37(11): 2372馬亞鑫, 王奎, 門正興, 等. Q345D鋼坯裂紋缺陷分析. 鑄造技術, 2016, 37(11):2372 [10] Li J Z, Zheng X P. Analysis of 27SiMn hot rolled seamless steel pipe inner burr. Mater Prot, 2019, 52(12): 168李金展, 鄭喜平. 27SiMn熱軋無縫鋼管內壁毛刺的原因分析. 材料保護, 2019, 52(12):168 [11] Ji D J, Qi X F. Cause analysis and improvement measures of inner folding defects of ?168 mm × 5 mm 0. 20% C steel tube. Special Steel, 2021, 42(1): 32季德靜, 齊曉峰. ?168 mm×5 mm 20鋼管內折缺陷原因分析及改進措施. 特殊鋼, 2021, 42(1):32 [12] Wang Q M, Cheng G G, Li J Y, et al. Formation mechanism of large inclusions in 80t 20Cr?8Ni stainless steel casting for nuclear power. Steel Res Int, 2019, 90(12): 1900349 doi: 10.1002/srin.201900349 [13] Chu Y P, Chen Z Y, Liu N, et al. Formation and control of spinel inclusions in high-speed heavy rail steel. Iron Steel, 2020, 55(1): 38儲焰平, 諶智勇, 劉南, 等. 高速重軌鋼中尖晶石夾雜物的形成及控制. 鋼鐵, 2020, 55(1):38 [14] Long H, Cheng G G, Qiu W S, et al. Characteristics, sources analysis of large size inclusions and technical improvement during bearing steel production. China Metall, 2020, 30(9): 53龍鵠, 成國光, 丘文生, 等. 軸承鋼中大尺寸夾雜物的特征、來源及改進工藝. 中國冶金, 2020, 30(9):53 [15] Ren Q, Jiang D B, Zhang L F, et al. Evolution and formation mechanism of inclusions in a Q235 steel. Iron Steel, 2020, 55(7): 47任強, 姜東濱, 張立峰, 等. Q235鋼中夾雜物演變規律和生成機理分析. 鋼鐵, 2020, 55(7):47 [16] Yin Z Y, Zhang L F, Li C, et al. Analysis of evolution and formation mechanism of calcium-containing inclusions of Q345D steel. Iron Steel, 2020, 55(11): 47音正元, 張立峰, 李超, 等. Q345D鋼中含鈣類夾雜物的演變和生成機理分析. 鋼鐵, 2020, 55(11):47 [17] Jiang M, Liu J C, Li K L, et al. Formation mechanism of large CaO?SiO2?Al2O3 inclusions in Si-deoxidized spring steel refined by low basicity slag. Metall Mater Trans B, 2021, 52(4): 1950 doi: 10.1007/s11663-021-02230-6 [18] Miao Z Q, Cheng G G, Li S J, et al. Formation mechanism of large-size CaO–Al2O3–MgO–SiO2 inclusions in high carbon chromium bearing steel. ISIJ Int, 2021, 61(7): 2083 doi: 10.2355/isijinternational.ISIJINT-2020-729 [19] Wang L Z, Li J Q, Yang S F, et al. Effect of calcium treatment on characteristics of non-metallic inclusions in steel containing high Al. Iron Steel, 2019, 54(11): 27王林珠, 李軍旗, 楊樹峰, 等. 高鋁鋼中鈣處理對非金屬夾雜物特征的影響. 鋼鐵, 2019, 54(11):27 [20] Wang Y, Zhang L F, Ren Y, et al. Mechanism of inclusion evolution during refining process of 37Mn5 steel production. Iron Steel, 2020, 55(5): 39王祎, 張立峰, 任英, 等. 37Mn5鋼精煉過程夾雜物轉變機理. 鋼鐵, 2020, 55(5):39 [21] Wang Y, Zhang L F, Yang W, et al. Evolution of non-metallic inclusion composition during cooling and solidification process of Q345 steel. Steelmaking, 2020, 36(2): 29王祎, 張立峰, 楊文, 等. Q345鋼液凝固及鑄坯冷卻過程中非金屬夾雜物的組成演變. 煉鋼, 2020, 36(2):29 [22] Xiao W, Bao Y P, Wang M, et al. Inclusions evolution and control of non-aluminum deoxidized GCr15 bearing steel. Iron Steel, 2021, 56(1): 37肖微, 包燕平, 王敏, 等. 非鋁脫氧GCr15軸承鋼的夾雜物演變和控制. 鋼鐵, 2021, 56(1):37 [23] Yin C L, Zhai W L, Jiang D C, et al. Source and control of large-size inclusions in 42CrMo steel. China Metall, 2021, 31(1): 36印傳磊, 翟萬里, 蔣棟初, 等. 42CrMo鋼大尺寸夾雜物的來源與控制. 中國冶金, 2021, 31(1):36 [24] Niu K J, Yang W, Zhang L F, et al. Thermodynamics and industrial practice of formation of inclusions during solidification of tire cord steels. Iron Steel, 2020, 55(6): 61牛凱軍, 楊文, 張立峰, 等. 簾線鋼凝固過程夾雜物生成熱力學及工業實踐. 鋼鐵, 2020, 55(6):61 [25] Zhang G F, Ji S, Zhang L F, et al. Study on transformation of non-metallic inclusions in 20CrMnTiH gear steel during solidification and cooling. Steelmaking, 2020, 36(3): 32張國鋒, 季莎, 張立峰, 等. 20CrMnTiH齒輪鋼凝固和冷卻過程中非金屬夾雜物的轉變研究. 煉鋼, 2020, 36(3):32 -
點擊查看大圖
計量
- 文章訪問數: 2130
- HTML全文瀏覽量: 226
- PDF下載量: 59
- 被引次數: 0
