Ti-Mg-Al复合脱氧X70级抗酸海底管线钢氢捕获效率及HIC敏感性  

Hydrogen Trapping Efficiency and HIC Sensitivity of Ti-Mg-Al Composite Deoxidized X70 Acid Resistant Submarine Pipeline Steel

作　　者：肖虎 黄峰[1,2] 彭志贤 戈方宇 刘静[1,2] XIAO Hu;HUANG Feng;PENG Zhixian;GE Fangyu;LIU Jing(The State Key Laboratory of Refractories and Metallurgy,Wuhan University of Science and Technology,Wuhan 430081,China;Hubei Engineering Technology Research Centre of Marine Materials and Service Safety,Wuhan University of Science and Technology,Wuhan 430081,China)

机构地区：[1]武汉科技大学省部共建耐火材料与冶金国家重点实验室,武汉430081 [2]武汉科技大学,湖北省海洋工程材料及服役安全工程技术研究中心,武汉430081

出　　处：《材料导报》2021年第10期10158-10165,共8页Materials Reports

基　　金：国家自然科学基金(51871172);湖北省中央引导地方科技发展专项(2018ZYYD026)。

摘　　要：采用NACE TM 0284-2016标准评估了一系列不同Al含量的Ti-Mg-Al复合脱氧X70级别抗酸海底管线试验钢的氢致开裂(HIC)敏感性,并通过测量氢扩散通量(J∞L)和有效氢扩散系数(D eff)研究了其氢捕获及扩散动力学行为。结果表明:Al的添加因能促进针状铁素体形成而显著提高试验钢的抗拉强度;随着Al含量增加,试验钢中的夹杂物不仅数量增加,成分也发生变化,由以均匀分布的单一Mn-S和Al-Ti-Mg-O-Mn-S复合夹杂物为主转向以带状分布的单一Al-O夹杂和Al-Ti-O-Mn-S型复合夹杂为主;当Al含量增加至0.03%时,试验钢的屈服强度降低,且[H]容易在脆性Al_(2)O_(3)夹杂物周围引发内部微裂纹,并产生表面氢鼓泡。Al的添加主要是通过影响钢中非金属夹杂物的特性,从而改变氢在钢中的捕获和扩散动力学行为,进而影响钢的HIC敏感性。在本实验范围内,Al的添加量不宜超过0.03%。NACE TM 0284-2016 standard was used to evaluate the hydrogen induced cracking(HIC)susceptibility of series of X70 grade anti-acid submarine Ti-Mg-Al composite deoxidization tested pipeline steels with different Al contents.The hydrogen diffusion kinetic behavior of X70 MOS pipeline steel was investigated through measuring the permeability(J∞L)and the apparent hydrogen diffusivity(D eff).The results indicated that the tensile strength of tested steels could be improved significantly due to the formation of acicular ferrite by the addition of Al.With increasing of Al contents,the amount of inclusions increased significantly,and single Mn-S and Al-Ti-Mg-O-Mn-S compound inclusions with uniform distribution changed into single Al-O and Al-Ti-O-Mn-S compound inclusions with chain distribution.When the content of Al was up to 0.03%,the yield strength of tested steel decreased,and H could be easily trapped around the brittle Al_(2)O_(3) inclusions,and then caused internal microcracks and hydrogen bubbles on the surface of tested steel.The addition of Al for Ti-Mg composite deoxidization steel mainly made the characteristics of non-metallic inclusions happen,and then changed the dynamic behavior of hydrogen diffusion,finally affected the HIC susceptibility of tested steels.In this research range,the addition amount of Al should not exceed 0.03%.

关 键 词：Ti-Mg-Al复合脱氧 X70 MOS管线钢 非金属夹杂物 HIC敏感性 

分 类 号：TG142.1[一般工业技术—材料科学与工程]