1. Technical requirements for shipbuilding steel
Due to the harsh working environment of ships, the hull of the ship is subject to chemical and electrochemical corrosion from seawater, as well as corrosion from marine organisms and microorganisms; The hull is subjected to significant wind and wave impacts and alternating loads; Due to factors such as complex processing methods caused by the shape of the ship, strict requirements are placed on the steel used for the hull structure. Firstly, good toughness is the most critical requirement. In addition, it requires high strength, good corrosion resistance, welding performance, processing and forming performance, and surface quality. To ensure quality and sufficient toughness, it is required that the chemical composition of Mn/C be above 2.5, with strict requirements for carbon equivalent, and produced by steel mills recognized by the ship inspection department. The strength grades of structural steel used in ship hulls are divided into general strength structural steel and high-strength structural steel according to their minimum yield point. The structural steel used for ship hulls is divided into two types: general strength steel and high-strength steel. General strength steel is classified into four grades by quality: A, B, D, and E; High strength steel is divided into two strength grades and three quality grades; AH32DH32EH32AH36DH36EH36.
The general strength structural steel according to the specifications and standards of China Classification Society is divided into four quality grades: A, B, C, and D (i.e. CCSA CCSBCCSCCCSD); The high-strength structural steel specified by the China Classification Society has three strength grades and four quality grades.
Among them, the following points are important:
Requirements for strength. Higher strength can reduce the weight of the ship, decrease welding workload, and increase load-bearing capacity. The adoption of high-strength steel is also constrained by the rigidity and corrosion resistance of the ship's hull.
The ship's shape is relatively difficult, with multiple types of single curves or hyperboloids, requiring various forming operations such as cold bending, hot bending, and correction. It also requires the adaptability of steel to shipbuilding processes, including welding and repair.
The requirements for plasticity and toughness are sufficient to compensate for the effects of work hardening and thermal cycling caused by various operations during the establishment process on the material. For important parts such as the bow column, the section with the highest longitudinal bending stress on the hull, and the bottom and side anti cracking plates, high crack resistance is required. It is required to have a lower ductile transition temperature and sufficient impact energy under low temperature conditions.
Corrosion resistance to seawater.
2. Demand for shipbuilding steel
Entering the 1990s, the growth of international shipping volume exceeded the increase in capacity, and the shipbuilding market saw active new ship construction and old ship transactions. In the first five years, new ship transactions reached 32 million displacement tons. Only the China Shipbuilding Industry Corporation system has built 6.76 million tons of ships, and can produce 3.5-4 million tons in the next five years. Accounting for 1/10 of the world's shipbuilding volume.
China's shipbuilding industry is capable of establishing 280000 ton oil tankers, 150000 ton bulk carriers, 1200 ton drilling platforms, 4200m3 LPG ships, 3000m liquefied gas ships, and fully automated high-speed hydrofoil ships.
The shipbuilding capabilities of Chinese shipbuilding companies, the Ministry of Transport, and the Ministry of Agriculture are around 6 million tons. It can establish 24 categories and thousands of non ship products for industries such as metallurgy, electricity, petrochemicals, hydropower, coal, urban construction, and light industry. But its production capacity is slightly lower than Japan's 14 million tons and South Korea's 13 million tons.
At present, the annual demand for shipbuilding steel is 2 million tons, of which shipbuilding steel plates are around 1-1.2 million tons. There are basically four types of steel and five levels of ship plates that can be produced domestically. The demand for general strength ship plates at 240Mpa level is still the main demand, while high-strength ship plates at 450Mpa and 600Mpa levels can also be produced. Seoul, Reuters - Steel plates for shipbuilding are a rare bright spot in the steel market, with supply remaining tight despite declining freight rates and the financial crisis forcing shipping companies to cut some orders.
Analysts say that with the economic downturn, the prospects for commercial steel products are bleak, and car sales have already fallen sharply. However, the prices of shipbuilding steel plates are expected to remain firm in the next six months, and even rise against the trend. Even if the shipbuilding industry is sluggish in the future, especially in South Korea, the world's largest shipbuilding country.
The steel industry has hit its peak, and new orders have sharply decreased by 40% compared to last year. Due to the tight credit situation, I think there may be more order cuts, and 5% of the orders already placed may be cancelled, "said Lee Jong whan, an analyst at Good Morning New Korea Securities However, cutting orders has little impact on major shipyards and steel demand, as their outstanding orders have been scheduled for more than three years. Thanks to strong demand from emerging markets such as China, steel prices surged to record highs this summer; however, steel prices have since fallen by more than 20% from this year's high. Given the sluggish demand from car manufacturers, construction companies, and home appliance manufacturers, steel manufacturers are considering reducing production to boost prices.
Despite the sluggish steel prices, the shipbuilding industry remains a bright spot. In September, South Korea's Dongguo Steel (001230. KS: Quote) raised the price of shipbuilding steel plates by 12%, marking the fourth price increase of the year, mainly due to high raw material prices and strong demand. Despite the sluggish steel prices, the shipbuilding industry remains a bright spot. In September, South Korea's Dongguo Steel (001230. KS: Quote) raised the price of shipbuilding steel plates by 12%, marking the fourth price increase of the year, mainly due to high raw material prices and strong demand
According to POSCO (005490) According to data from KS, the supply and demand gap of steel plates in South Korea is expected to peak at 7 million tons next year, and then narrow to 4 million tons and 3 million tons by 2026. While the shipbuilding industry continues to thrive, the expansion of steel plant capacity is slow, which has kept supply tight and pushed prices to break through a record high of $1000 per ton. However, this tight situation is expected to be alleviated as steel plants are arranging large-scale expansion. Pohang Steel is scheduled to become the largest steel plate supplier by 2026, with a production capacity of 7 million tons. Hyundai Steel (004020. KS) has also invested 5.8 trillion Korean won ($4.8 billion) to build its first steelmaking blast furnace. South Korea consumes approximately $1000 per ton per year. 13.3 million tons of shipbuilding steel plates, limited by slow expansion of domestic production capacity, About half of the demand relies on imports. Pohang Steel expects to produce 4.7 million tons of shipbuilding steel plates this year, which only accounts for 14% of its 33 million tons of raw steel production.
However, due to the outbreak of the financial crisis, credit channels have been compressed, weaker shipyards and shipping companies have been squeezed out of the market, and trading activities have been hit, so the growth trend of steel plate demand in the shipbuilding industry may slow down. Citigroup analyst Sokje Lee said, "We expect that due to the high base period in 2008 and the volatility of the financial market, the order volume in 2009 will be reduced by 10-15% compared to 2008, but it is expected to rebound strongly by 2026." The demand for container ships and bulk dry cargo ships may be significantly reduced, as global commodity and raw material trade activities such as iron ore and coal will be affected by the economic slowdown. The Baltic Exchange Index of Global Raw Material Shipping has plummeted 80% from its record high in May. It is expected that the index will continue to decline next year, Between 1000-2000 points. However, the demand for oil tankers and offshore energy plants is expected to remain quite strong, mainly due to the demand from the Middle East, which will drive overall steel consumption growth.
3. Conclusion
With the rapid development of the shipbuilding industry, the demand for shipbuilding steel continues to be strong. Increasing the production quantity of shipbuilding steel and researching and producing high value-added advanced wear-resistant steel is of great significance to the development of the entire shipbuilding industry.
