Warm tempforming effect on the hydrogen embrittlement of 1.8-GPa-class ultra-high-strength low-alloy steel
Warm tempforming effect on the hydrogen embrittlement of 1.8-GPa-class ultra-high-strength low-alloy steel
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DOI：
10.1016/j.msea.2017.07.091
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发表时间：
2017-08
期刊：
影响因子：
6.4
通讯作者：
Y. Kimura;Tadanobu Inoue;E. Akiyama
中科院分区：
文献类型：
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作者：
Y. Kimura;Tadanobu Inoue;E. Akiyama
采用预充氢缺口慢应变速率试验、大气加速腐蚀试验和热脱附谱研究了1.8 Gpa级超高强度低合金钢的氢脆特性。化学成分为Fe-0.4C-2Si-1Cr-1Mo(质量分数)的含钼钢在773℃淬火回火1h后，经多道次轧制变形，在773K下的累计变形量为76%，获得了具有强烈<；110&//轧制方向纤维织构的超细长晶组织。随后对温热成形(Tf)样品进行1h的退火，以阐明纳米碳化物相对于添加剂Mo的氢捕获效应。当Tf样品(TFA样品)在843℃下热处理时，通过在超细细长晶基质中形成纳米级的富Mo析出物，显著提高了吸氢能力。在大气腐蚀环境中，TF和TFA样品都表现出了很高的抗氢脆性潜力，其超高抗拉强度为1.8 GPA。与超高抗拉强度(1.8 Gpa)的回火马氏体样品相比，Tf和TFA样品对氢脆的敏感性要小得多。结合含纳米富钼沉淀的各向异性超细晶结构，讨论了Tf和TFA样品的氢捕获态和高抗氢脆性。
Hydrogen embrittlement properties were investigated for 1.8-GPa-class ultra-high strength low-alloy steels by means of slow-strain-rate test of the pre-hydrogen-charged notched specimens, accelerated atmospheric corrosion test, and thermal desorption spectrometry. A Mo-bearing steel with a chemical composition of Fe-0.4C-2Si-1Cr-1Mo (mass%) was quenched and tempered at 773 K for 1 h and then deformed by multi-pass caliber rolling with a cumulative rolling reduction of 76% at 773 K to create an ultrafine elongated grain structure with a strong <110>//rolling direction fiber texture. The warm tempformed (TF) sample was subsequently annealed for 1 h to clarify the hydrogen trapping effect of nanoscale carbides relative to additive Mo. When the TF sample was annealed at 843 K (TFA sample), the hydrogen absorption capacity was enhanced significantly through the formation of nanoscale Mo-rich precipitates in the matrix of ultrafine elongated grains. A high potential for hydrogen embrittlement resistance in an atmospheric corrosion environment was demonstrated in both the TF and TFA samples with an ultra-high tensile strength of 1.8 GPa. The TF and TFA samples were much less susceptible to hydrogen embrittlement as compared to the tempered martensitic samples at an ultra-high tensile strength of 1.8 GPa. The hydrogen trapping states and the high resistance to hydrogen embrittlement in the TF and TFA samples are discussed in association with the anisotropic, ultrafine grained structures with the nanoscale Mo-rich precipitates.