Across the centuries, the construction process of the ships has evolved – and so did the selection of materials. Which are commonly used nowadays, and what’s their specification?
For thousands of years, humans used to build ships with wood. The switch to welded sheets was made not such a long time ago – but along with it, wooden constructions have been put aside. The steel is a relatively new invention when it comes to ships, but it completely revolutionized the industry. With its implementation, the producers were able to construct more salt and water-resistant offshore objects.
The construction progress
It’s worth noting that the progress in construction was possible mainly because of the definition of fragility threshold. This parameter allows us to specify below which temperature the steel completely loses its deformability – in other words, in what conditions the construction can crack.
Nowadays, the production and distribution of steel for the maritime industry is an important branch of the business. The variety of kinds makes it possible for the shipyards to adjust the fitting material. Obviously, the parts of the ships are built from different materials – steel is not the only one in use. Also, a lot depends on the type of construction and its destination. The majority of the materials, however, have to have particular features. Resistant to corrosion and low temperatures are the most crucial. Below you will find 3 most commonly used materials for the maritime industry.
The name “duplex” refers to the specific construction of this steel for offshore, commonly used in the maritime industry. Its microstructure, consisting of 50% austenitic/ 50% ferrite, provides a stronger resistance to chloride stress corrosion cracking than most of the materials available on the market. The yield strength of duplex steel is roughly double of their counterpart austenitic grades. It’s a cost-effective material for the construction of ships and boats – corrosion-resistant and easy to form.
Next-generation of duplex steel, used since the 1980s’. The term refers to highly alloyed, very efficient steel. Its pitting resistance equivalent is >40. The popularity of superduplex steel grows because of its outstanding features, most of all – high resistance to acids. It’s also perfect steel for saltwater, resistant to corrosion.
Both duplex and super duplex steel are widely available on the market and can serve as a perfect material for the maritime industry.