페라이트-펄라이트 조직 저탄소강의 수소 취성에 미치는 Nb 첨가와 예비 변형의 영향 = Effect of Nb addition and Pre-strain on Hydrogen Embrittlement of Low-carbon Steels with Ferrite-pearlite Structure

다국어 초록 (Multilingual Abstract)

The effect of pre-strain on the hydrogen embrittlement of Nb-free and Nb-added low-carbon steels with ferrite-pearlite structure was investigated in this study. After the steels were electrochemically charged with hydrogen, slow-strain rate tensile (SSRT) tests were conducted on them to examine hydrogen embrittlement behavior. The SSRT test results revealed that the Nb-added steel had a lesser decrease of elongation and reduction of area than the Nb-free steel. The formation of NbC carbide and grain refinement caused by the Nb addition improved resistance to hydrogen embrittlement. The loss of elongation and the reduction of area after hydrogen charging occurs when pre-strain is increased. The pre-strain increases dislocation density and thus increases the amount of reversible hydrogen trap sites associated with hydrogen embrittlement. 10% pre-strained specimens exhibited a significant loss in elongation and reduction of area, regardless of Nb addition. Based on the results of electron back-scatter diffraction, fractographic, and silver decoration analyses for Nb-free and Nb-added steels, the hydrogen embrittlement mechanism in low-carbon steels with different amounts of pre-strain is discussed in terms of dislocation density and hydrogen distribution.

참고문헌 (Reference)

1 M. A. Mohtadi-Bonad, 31 : 13831-, 2013

2 J. Yang, 712 : 630-, 2018

3 S. I. Lee, 742 : 334-, 2019

4 S. Y. Lee, 711 : 22-, 2018

5 C. Zener, 15 : 22-, 1944

6 T. Michler, 35 : 821-, 2010

7 M. Okayasu, 791 : 139598-, 2020

8 T. Meeraj, 60 : 5160-, 2012

9 I. Yoo, 51 : 2118-, 2020

10 S. I. Lee, 766 : 138367-, 2019

11 K. B. Kang, 36 : 1303-, 1997

12 S. S. Hansen, 11 : 387-, 1980

13 M. A. Stopher, 106 : 205-, 2016

14 J. S. Kim, 47 : 913-, 2007

15 C. Park, 128 : 33-, 2017

16 J. H. Shim, 62 : 67-, 2018

17 S. Zhang, 164 : 108345-, 2020

18 S. Zhang., 626 : 136-, 2015

19 N. Zan, 40 : 10687-, 2015

20 X. Li, 616 : 116-, 2014

21 Y. Wang, 39 : 13909-, 2014

22 P. Tao, 16 : 102820-, 2020

23 B. Kumai, 45 : 27920-, 2020

24 S. I. Lee, 758 : 56-, 2019

25 이상인, "페라이트-펄라이트 조직 저탄소강의 미세조직과 인장 특성의 상관관계에 미치는 미량합금원소와 변태 온도의 영향" 한국재료학회 27 (27): 184-191, 2017

26 황은혜, "탄소함량이 자동차용 초고강도 철강소재의 부식 및 수소 확산 거동에 미치는 영향" 대한금속·재료학회 56 (56): 570-579, 2018

27 이승용, "수소 주입 방식에 따른 세 고망간강의 수소 취화 거동 비교" 대한금속·재료학회 55 (55): 695-702, 2017

28 최병학, "베이나이트계 X70강 수소가압분위기 인장시험의 수소취성균열 전파" 대한금속·재료학회 56 (56): 1-7, 2018

29 이상인, "극저온용 오스테나이트계 Fe-30Mn-0.2C(-1.5Al) 고망간강의 수소 취화 특성" 한국열처리공학회 31 (31): 283-289, 2018

30 M. A. Mohtadi‑Bonab, "Important Factors on the Failure of Pipeline Steels with Focus on Hydrogen Induced Cracks and Improvement of Their Resistance: Review Paper" 대한금속·재료학회 25 (25): 1109-1134, 2019

31 이정훈, "Hydrogen-Induced Cracking of Laser Beam and Gas Metal Arc Welds on API X65 Steel" 대한금속·재료학회 57 (57): 491-498, 2019

32 Junmo Lee, "Effects of Vanadium Carbides on Hydrogen Embrittlement of Tempered Martensitic Steel" 대한금속·재료학회 22 (22): 364-372, 2016

33 박기정, "Effects of Molybdenum on HIC Susceptibility in Normalized Pressure Vessel Steels for Sour Service Applications" 대한금속·재료학회 57 (57): 405-411, 2019

34 Sang‑In Lee, "Effect of Strain Aging on Tensile Behavior and Properties of API X60, X70, and X80 Pipeline Steels" 대한금속·재료학회 24 (24): 1221-1231, 2018

35 박철호, "Effect of Prestrain on Hydrogen Embrittlement Susceptibility of EH 36 Steels Using In Situ Slow‑Strain‑Rate Testing" 대한금속·재료학회 25 (25): 584-593, 2019