Hydrogen storage tanks need to account for hydrogen corrosion and hydrogen embrittlement

This post was last edited by zhangjuhua on 2018-3-30 at 19:42. In my opinion, hydrogen corrosion seems to be a concern only at high temperatures. Hydrogen corrosion and hydrogen embrittlement generally do not occur simultaneously. Hydrogen embrittlement is a concern only at low temperatures; the higher the temperature, the less likely hydrogen embrittlement is to occur. It occurs at low temperatures, and materials with poor plasticity and toughness, high-strength steels, as well as steels under severe stress conditions require special attention, as fracture can occur even under very low stresses

Hello: How exactly should we understand high temperature and low temperature as you mentioned? Are there any specific figures?

High temperature refers to above 200 degrees, as clearly stated in clause 7.8.3 of HG/T20581-2011.

This post was last edited by zhangjuhua on 2018-4-1 at 13:07. Baidu Baike: Hydrogen corrosion: https://baike.baidu.com/item/%E6%B0%A2%E8%85%90%E8%9A%80/2096639?fr=aladdin refers to the situation where steel is exposed to a high-temperature, high-pressure hydrogen environment; hydrogen atoms react with unstable carbides on the surface of the equipment or within the steel itself to form methane, resulting in decarburization of the steel and permanent damage to its mechanical strength. The methane generated inside the steel cannot escape and accumulates there, creating high local pressures that lead to severe bulging and cracking. According to Baidu Baike, hydrogen corrosion is divided into hydrogen blistering, hydrogen embrittlement, and hydrogen erosion. But in my personal opinion, even though hydrogen embrittlement can occur at high temperatures, the high activity of free hydrogen at such temperatures leads it to expand and be released, rather than penetrating into the crystal lattice. Hydrogen embrittlement is not visible to the naked eye, while hydrogen corrosion may manifest as bubbling. Temperatures between -100 and -20°C are associated with hydrogen embrittlement at low temperatures; the allowable hydrogen content in such conditions is likely to be more stringent, as this period is accompanied by a transition from ductile to brittle behavior in the material, resulting in more pronounced synergistic effects. The transition from ductile to brittle behavior occurs in ordinary carbon steel at temperatures between -20 and -30°C, while alloy steels can exhibit this transition at even lower temperatures. The resistance of carbon steel to hydrogen corrosion decreases as the carbon content in the steel increases ； Low-alloy steels containing small amounts of elements such as titanium, niobium, vanadium, and molybdenum, which have a strong affinity for carbon, possess good resistance to hydrogen corrosion. In 20582, hydrogen corrosion is defined as an environment with a design temperature greater than 200°C and exposure to a hydrogen atmosphere. https://bbs.hcbbs.com/forum.php?mod=viewthread&tid=1912799&extra=page%3D1 SH/T 3193-2017 Guidelines for the Design of Equipment Used in Hydrogen Sulfide-Containing Environments in the Petrochemical Industry