#文章首发挑战赛#
One night 80 years ago, a shocking noise suddenly sounded in the Swan Island shipyard in the United States. Woke up the workers who were resting at the end of the day.
They hurried to the dock before they had time to get dressed, and what they saw was that the tanker, which had just been completed for less than half a month, had broken into two sections! The ship was about to be launched tomorrow for the final test.
This is not an accidental event, a total of 1,500 of these tankers have serious cracks, you know, at that time, the cost of a free ship was about 2 million US dollars, which is a lot of money.
Fortunately, however, the tankers were not split in two in the rough waters, otherwise the casualties would have been incalculable.
After these things happened, rumors spread all the time, and people were panicked. You must know that human power will never destroy these giant ships in half without warning, and everyone asserts that they must have supernatural abilities, either aliens have attacked us, or there are demons and monsters from unknown places who want to give us some color to see.
Seeing that everyone's speculation is getting more and more outrageous, the government has also decided to thoroughly investigate the matter from beginning to end.
The ship was broken in half, and the experts in charge of the investigation first asked the welders if there was any accident during the welding process.
This frightened the young people in charge of welding, and they told the experts that every step of the process was carried out in strict accordance with the production regulations manual, and there would be absolutely no problems.
The experts checked left and right, and even suspected that the temperature of the outside sea water was above, but they were always at a loss, and finally even the experts suspected that there was really some UFO from outer space that attacked us that night.
But in fact, the culprit in the destruction of the ship's hull is just that: hydrogen. This is an ordinary element that we are not very familiar with, but at least often hear about in our lives.
"Mystic power" - hydrogen
You may wonder, isn't this hydrogen a chemical element in nature?
Hydrogen is the simplest element in the periodic table and one of the most abundant elements in the universe. Its atomic composition is only one proton and one electron, and it can participate in many chemical reactions.
It can combine with oxygen to form water molecules, which are an indispensable part of life. At the same time, hydrogen can also react with other elements to form various compounds. In industrial production, hydrogen is often used as a reducing agent and is involved in a variety of synthesis and production processes.
But when we introduce hydrogen into the realm of metals, there is a phenomenon involved, which is hydrogen embrittlement.
During the welding process, small hydrogen atoms penetrate into the metal lattice to form hydrogen molecules, which then react with the metal atoms to form hydrides.
They gather near the grains of the metal, destroy the original structure, make it expand and become brittle, and some metal materials become fragile and easy to break when subjected to external stress or load, and even form fine cracks inside, this phenomenon is also known as "hydrogen embrittlement".
Metals that are particularly susceptible to hydrogen embrittlement include steel and aluminum alloys. In some industrial manufacturing and construction sectors, hydrogen embrittlement can have an impact on the strength and durability of a structure if it is not handled carefully.
In fact, in the eighties of the nineteenth century, the scientist Johnson stumbled upon a miraculous phenomenon, the hard-to-break strips are soaked in vinegar, and the hydrogen in the vinegar will dissolve into the iron, making it extremely fragile and can be broken with a slight break.
This is the first time that science has recognized the occurrence of hydrogen embrittlement, but despite this, people have not really recognized the potential harm that this phenomenon can bring.
Hydrogen embrittlement events occur suddenly without warning, such as the rupture of the cruise ship due to hydrogen embrittlement, and similar situations occur in many other fields, such as aviation, petroleum, chemical industry, nuclear energy, etc.
There was a fire in the Los Angeles Times in 1903, when the Los Angeles Times' offices were using hydrogen as a power source for the printing press. Just as it was being printed, a fire suddenly broke out, and the entire building was engulfed almost instantaneously. The reason turned out to be that the hydrogen in the printing press exploded after mixing with oxygen in the air.
In the 1937 "Syniburg Disaster", a giant airship named "Syneburg" fell due to a broken engine spindle while landing, and eventually exploded and caught fire, causing heavy casualties.
In 1975, in an oil refinery in Chicago, USA, a 15cm stainless steel pipe also suddenly ruptured, causing an explosion and fire, which not only caused casualties, but also caused serious pollution to the local environment.
In 1988, an accident occurred in a French factory, when a metal tank containing 3,000 liters of hydrogen suddenly exploded, affecting all nearby residents and buildings, and causing countless casualties.
How can modern "hydrogen embrittlement" be avoided?
In our daily life, hydrogen is undoubtedly an indispensable part of metal materials, but once the phenomenon of hydrogen embrittlement occurs, it will cause a huge disaster. So, how exactly can we avoid this headache when using hydrogen?
Through long-term production and labor experience, steelmakers in the mainland have found that although hydrogen is easy to diffuse in some metals, it is relatively stable in metals such as chromium, titanium, and vanadium.
Therefore, when using hydrogen, it is important to be able to choose the right metal material. In order to prevent the sudden occurrence of hydrogen embrittlement, we need to avoid metals that react easily with hydrogen and choose materials that are more stable.
Hydrogen embrittlement generally occurs between -50°C~100°C, because in this temperature range, the diffusion rate of hydrogen is slower. In cold environments, hydrogen can be "baked" out of the metal by baking at too high a temperature, allowing the hydrogen to leave, which naturally reduces the risk of hydrogen embrittlement.
In order to further reduce the probability of hydrogen embrittlement, the industrial production of the mainland has adopted an ingenious measure - the dehydrogenation process. After the metal is finished, by heating the metal to a temperature of 200~240°C, most of the hydrogen will be expelled. It's like a "detoxification" of the metal to ensure that hydrogen is no longer lurking in it, thus reducing the risk of hydrogen embrittlement.
Scientists have been working tirelessly to find the best way to minimize the occurrence of hydrogen embrittlement. Back in 2015, a team of researchers at the University of Oxford began a study with the goal of producing a steel that would not be affected by hydrogen embrittlement.
This innovative steel body allows hydrogen atoms to be trapped at the beginning of the metal. It's like installing a "sponge" inside the steel that absorbs hydrogen atoms, and once the hydrogen atoms enter, they are quickly and firmly absorbed, thus avoiding serious harm to the material's properties.
Even more surprisingly, the team found that by using a mixture of carbon and metal, hydrogen atoms can be effectively adsorbed on the surface of carbon by using the properties of carbon, thereby reducing the damage to the metal. This finding provides a new idea for the development of more advanced prevention strategies.
In the case of satisfying the technical conditions of the product, we can also use a coating that will not cause hydrogen seepage, for example, the Dacromet coating layer can replace the traditional galvanizing, not only will not cause hydrogen embrittlement, but also the corrosion resistance is increased by 7~10 times, and the adhesion is also better, so as not to affect the stability of the assembly.
In addition, it is not difficult to find that some special air control systems are often used in modern industrial sites to ensure the stability of gas concentration.
Through scientific means, the system can strive to keep the concentration of hydrogen within a safe range, setting up an invisible safety barrier for the industrial field to ensure the smooth progress of the production process.
Everything is multifaceted, and hydrogen, known as the first element of the universe, is both a harmless existence and may release powerful energy. What we can do is to find the perfect solution in countless attempts to minimize the possibility of catastrophic accidents.