12-1b T Q235B ML15 Ca OH Table 1 Chemical composition of specimens % C Si Mn S P Cr Ni Fe

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立柔歆邴
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1 * Q235B ML15 Ca OH 2 DOI /j. gyjz STUDY OF GALVANIC CORROSION SENSITIVITY BETWEEN ANY COUPLE OF STUD WELDMENT OR BEAM Lu Xinying Li Yang Li Yuanjin Department of Civil Engineering Tsinghua University Beijing China Abstract The corrosion behavior of Q235B steel beam ML15 steel stud and the weldment used in a steel-concrete composite element as well as the galvanic couples referring to the stud body in a simulated rainwater and a saturated Ca OH 2 solution with different amount of chlorions was studied by electrochemical method. The results showed that the weldment was the weakest part to be destroyed in the stud-beam system the stud head was the following one the stud body and the beam were moderate. So the galvanic cells were easily to be established between the weldment and stud or beam in the simulated solutions at the present work and the galvanic current increases with the corrosion strength of the solutions. The galvanic corrosion rate of weldment was at least one order higher than that of the selfcorrosion when the galvanic cell was established. Keywords composite structure stud corrosion T 1 1a Fig. 1 beam's section * 2011BAJ09B luxy@ mail. tsinghua. edu. cn T Schematic of steel-concrete composite T-type Industrial Construction Vol. 45 No

2 12-1b T Q235B ML15 Ca OH Table 1 Chemical composition of specimens % C Si Mn S P Cr Ni Fe Balance Balance Balance NaCl 2 PH % 10-6 mol /L NaCl mol /L C 6 H 12 N 4 30 min NH 4 2 SO 4 15 min CS350 Tafel SCE 5 min 0. 5 mv /s Tafel 25 min ± 250 mv 0. 5 mv /s 0. 2 s cm s Tafel I Ca OH 2 CH Ca OH mol /L 3 NaCl Ca OH mol /L ± 15 mv

3 2 Table 2 Average linear polarization resistance in different simulated solutions kω cm 2 CH CH mol /L NaCl CH mol /L NaCl CH CH mol / L NaCl CH mol /L NaCl 4 5 ~ 8 kω cm 2 2 Ca OH Tafel 2 Tafel Ca OH 2 a CH b CH mol /L NaCl c CH mol /L NaCl d Fig. 2 2 Tafel Tafel polarization curves in different simulated solutions 2 Ca OH 2 3 ± 50mV a CH b CH mol /L NaCl c CH mol /L NaCl d Fig. 3 3 Galvanic potential in different solutions

4 a CH b CH mol /L NaCl c CH mol /L NaCl d Fig. 4 4 Galvanic current in different solutions 3 Table 3 Linear polarization resistance of different weldments kω cm 2 Ca OH mol /L NaCl - 6 ~ 10 μa /cm mol /L NaCl Ca OH 2 20 μa /cm Ca OH 2 Ca OH μa /cm mol /L NaCl Ca OH mol /L NaCl Ca OH mol /L NaCl 27 μm /a 36 μm /a μm /a 644 μm /a mol /L NaCl J J 3 4 Ca OH mol /L NaCl /5 1 / J D D D

5 Fig Curve of change in axial force of oblique support MPa MPa MPa MPa J J Fig. 15 z MPa z-axis stress cloud of main structure J Midas J M J J GB S. 9. J GB S D J D J. 12 Davis J R. Corrosion Understanding the Basics M. Ohio ASM International Davis J R. Corrosion of Weldments M. Ohio ASM J International

m K K K K m Fig. 2 The plan layout of K K segment p

m K K K K m Fig. 2 The plan layout of K K segment p 410151 K7 + 914 - K7 + 984 12 5. 3 Midas DOI 10. 7617 /j. issn. 1000-8993. 2013. 09. 020 THE ANALYSIS OF THE DESIGN AND CONSTRUCTION SECURITY OF DEEP FOUNDATION IN PURUI TUNNEL OPEN-CUT SEGMENT Yang Ping