The marine grade aluminum sheets have been used in the shipbuilding industry for nearly 100 years. The high toughness, corrosion resistance and weldability of aluminum alloys provide a good choice for ships with strict weight requirements. How to select the right aluminum alloy?
1. High yield strength and elastic modulus
The yield strength and elastic modulus of the material are the most basic parameters for calculating the structural strength of the ship and determining the structural dimensions. The elastic modulus is 70-73 GPa.
Because the elastic modulus and density of various aluminum alloys are almost the same, and adding a small amount of alloying elements or changing the heat treatment state has little effect on them, improving the yield strength within a certain range is beneficial to reduce the weight of the ship structure.
However, high-strength aluminum alloys are generally difficult to have both excellent corrosion resistance and weldability. Therefore, marine grade aluminum alloys for ships are generally selected to have moderate strength and corrosion-resistant weldable aluminum alloys.
2. Excellent welding performance
For ships, the use of welded connections has obvious advantages over the use of riveted connections. The good weldability of the aluminum alloy means that the tendency of the cracks formed by the aluminum alloy during welding is small, that is, the aluminum alloy has good welding crack resistance.
AL-Zn-Mg series and AL-Mg-Si series alloys have significantly reduced strength after welding, and AL-Zn-Mg series alloys have poor corrosion resistance after welding, so these two series are subject to certain restrictions when used as welding marine materials. The AL-Mg alloy has no such disadvantages.
3. Excellent corrosion resistance
Ships are mostly used in harsh seawater and marine environments, so whether aluminum alloys are corrosion-resistant is one of the main signs that determine whether they can be used as marine aluminum alloys.
General requirements for marine aluminum sheet and welded joints in seawater and marine environments are without stress corrosion, spalling corrosion and intergranular corrosion tendency.
4. Good cold and hot forming properties
During the manufacturing process, the ship is subjected to cold processing (such as hemming, roll bending, stamping, etc.) and hot processing (such as hot bending). Therefore, it is required that the marine grade aluminum is easy to process and form, and no defects such as cracks are generated during processing. The performance requirements such as strength and corrosion resistance can still be met after processing.
As a big aluminum sheet manufacturer, Haomei Aluminum has different kinds of aluminum allosy such as 5052, 5083, 5456, 6061, 3003,etc., for shipbuilding. Welcome to inquire marine grade aluminium sheet price from us directly.
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