When the brand-new 100 mm thick f690 ultra-high-strength marine steel was presented to Zhao Jingfu again, it had completely changed.
Although not many changes can be seen on the surface, the internal changes are huge. According to the test data, both in terms of strength and welding preheating temperature changes, they have fully met the needs of the Blue Whale.
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This is the real f690, a piece of ultra-thick marine engineering steel that has reached the world's advanced technological level.
For three full months, Hong'an Steel's scientific researchers faced various failures but never gave up their faith, carried out research and development work around the clock, and finally produced qualified samples within the specified time.
This is a victory for Hong'an Steel and a victory for China's metallurgical scientific and technological personnel.
Han Fangyun, who comes from a steel family, cried the moment the data reached the standard.
Although she has developed many types of materials, f690 was her most difficult. In such a demanding time, she used all available manpower and material resources, and with the full support of Hong'an Iron and Steel Group, she finally won this
A tough nut to crack.
Hundreds of days of hard work have paid off. F690 has once again put Hong'an Steel at the forefront and become a benchmark for steel companies across the country.
Zhao Jingfu immediately told the good news to the Whale Dream Project headquarters in Longbin. This was another milestone after the major breakthrough in the design work.
After receiving the news, the command headquarters was immediately overjoyed. With the F690, the Blue Whale had a foundation to stand on. It also meant that the Chinese's own seventh-generation semi-submersible drilling platform had its own domestic skeleton and no longer had to suffer.
The restrictions of foreign companies depend on other people’s faces.
Zhao Jingfu's mission at Hong'an Steel has finally come to an end. He took these newly forged 100mm f690 high-strength marine steel plates and said goodbye to the hard-working Hong'an Steel's scientific and technical personnel and prepared to return to Longbin to continue a series of tests.
, only f690s that have completed all tests can be assembled into the Blue Whale.
At the farewell party, Zhao Jingfu could not say anything. Everyone was celebrating with laughter and crying tears of joy wantonly.
These three months of arduous research and day and night fatigue have made everyone lose a lot of weight. Although Zhao Jingfu has always been in the role of finding faults during the research process of f690, the engineers still admire him and gave up a comfortable environment to join them.
The mosquito-infested suburbs are scorched by flames all day long, which in itself is a responsibility for work.
Zhao Jingfu escorted these hard-won F690s back to Longbin day and night. Hu Yufeng took the leaders of Fengyang Shipyard to the cargo yard to greet them. This time Fengyang Shipyard undertook the most critical welding material selection and welding in the CTOD experiment of F690.
Craft projects.
The responsibility of this project falls on Zhao Jingfu who is familiar with the entire f690 forging process.
Facing the F690 in front of him, Zhao Jingfu knew that the time had come to truly test himself.
Having high-quality f690s is an indispensable basic condition for the Blue Whale, and welding is a more critical step. Without welding, these f690s are just a pile of materials sitting in the cargo yard.
When it comes to welding, Zhao Jingfu still thinks he has a big say.
The strength, stability and other issues of marine engineering steel structures have long received widespread attention, but the toughness issue has only recently received focus.
The so-called toughness refers to the material's ability to resist cracking and crack expansion under the action of external loads, that is, the material's ability to absorb energy during the elastic-plastic deformation process before fracture. It is a comprehensive expression of strength and plasticity.
Among them, welding is the most obvious representative.
The welded joints are not evenly distributed, and the physical changes and mechanical properties of the material caused during the welding process will be unpredictable. The next CTOD experiment can directly reflect the organizational toughness in the welding area.
This is the most direct review of the welding results. These welds not only bear the huge static load of tens of thousands of tons of the Blue Whale, but also bear the dynamic loads caused by waves, currents, typhoons, etc., and are very susceptible to fatigue damage.
In particular, the key stress parts of the Blue Whale are all made of 100 mm thick F690 ultra-high-strength marine steel plates. Steel plates of such thickness are very prone to minor cracks, pores, slag inclusions and other accidents.
If the toughness of the welding material is excellent enough, the pore cracks generated during the welding process will expand slowly or even not at all, which is enough to ensure the safety of the Blue Whale during its service life.
If the welding materials and processes used are defective, these occasional cracks will easily expand and cause damage to the entire steel structure.
There are hard lessons to be learned from this kind of thing.
When Zhao Jingfu was in school, his teacher warned these indifferent students that a single welding error would cause complete paralysis of the entire component. In 1969, the Bohai drilling platform used welding materials that did not have low-temperature toughness. The resulting inclusions and incomplete welding cracks have poor resistance, eventually causing the pipe to break.
There are also such cases abroad. A semi-submersible platform in the British North Sea also suffered from fatigue cracks in a branch pipe, causing the entire platform to capsize and more than 100 people were killed on the seabed.
"These are bloody lessons, and they are all matters where human life is at stake!" Zhao Jingfu still remembers the teacher's heartbreak when he explained these accidents. A single weld can change the existence of a giant monster, and even people's lives.
As a seventh-generation semi-submersible deep-sea drilling platform, the Blue Whale must avoid such a tragedy. In particular, the Blue Whale is the first to use 100 mm thick high-strength offshore plates. For steel plates of this thickness, the world's largest There is no precedent for CTOD experiments on it.
This illustrates the importance of conducting CTOD experiments on it.
There are also major realistic situations before us. Zhao Jingfu has no experience to draw from and can only rely on his own exploration.
This means immense patience and meticulousness, as well as perseverance and the reality of countless failures.
Zhao Jingfu also knows that he has partners with whom he gets along day and night, strong support from Fengyang Shipyard, and high hopes from Fuhai Group, all of which will serve as motivation for him to complete this arduous task.
Zhao Jingfu is also responsible for this important task, which is to save time and cost as much as possible while ensuring quality through CTOD experiments, which is of extremely important significance to the construction of the entire Blue Whale.