Many materials are used in shipbuilding, including fiber-reinforced composites (FRP), non-ferrous metals, plastics, and more. Yet almost 90% of materials consumed by maritime engineering are comprised of marine steels. Common steels for shipbuilding include carbon and mild steel grades that combine exceptional tensile strengths with good workability, but there are several critical parameters for materials to meet the standards of master shipbuilders.
Steel for shipbuilding must first be classified according to one or more of the relevant classification societies: American Bureau of Shipping (ABS), Lloyd’s Register, or Det Norske Veritas (DNV). These have established globally-accepted standards and rules that steel for shipbuilding must follow, from chemical composition to downstream plate thickness.
This blog post will outline the history of steel for shipbuilding and will highlight key material properties for shipbuilding in the modern age.
Brief History of Steel for Shipbuilding
Although there was a moderate use of steel for shipbuilding in the latter part of the 19th Century, timber and wrought iron remained the material of choice in maritime applications for decades. It was not until the outbreak of World War II that large vessels like cargo freighters and military ships were engineered almost exclusively from welded steel. This was largely a response to the ballistics capabilities of the time: steels were stronger and lighter than wrought iron, enabling the fabrication of faster and more durable vessels designed to operate in active theatres of war.
After the war, iron was completely supplanted by steel for shipbuilding due to the material’s inherent cost- and weight-savings. This catalysed a new era of ingenuity in shipbuilding characterised by block construction of prefabricated steel sections. Now, steel is used almost exclusively when it comes to construction of ship superstructures.
Key Properties of Steel for Shipbuilding
Plain carbon and mild steel are the most common grades of steel for shipbuilding, as they boast a raft of beneficial properties that make them uniquely suited for marine engineering. These include:
- High yield strengths and typical tensile strengths on a range of 490 – 620 MPa
- Easy joining and tight control of potential weld defects
- Superior metallurgical properties to overcome brittle fracture/fatigue
- Reasonable cost to ensure tangible ROIs
Masteel: Steel for Shipbuilding
Masteel is one of the world’s leading suppliers of steel for shipbuilding. All our grades are certified to ASTM/ASME specification and can be classified according to any of the relevant societies. Our steels for shipbuilding include:
- AH36: A common steel for shipbuilding that is typically formatted as heavy plates and fabricated surfaces for large, heavy-duty vessels like commercial ships and bulk carriers.
- DH36: Another common shipbuilding steel used to construct and retrofit ship superstructures.
- EH36: A desirable steel for shipbuilding that is available in prefabricated sections and heavy plates for hull construction and superstructure design.