The Titanic disaster & its relation to Material science

When a material fractures, the consequences are catastrophic. This is especially true when the material in question is a structural component that is subjected to high loads. The failure of a single component can lead to the failure of an entire structure.

Ductile to Brittle Transition (DBT) is a major concern in engineering. The Titanic is a famous example of a disaster that was caused by DBT.

This article throws light on the dangers of DBT and how it can be avoided as it is important for engineers to take steps to prevent it from occurring in their designs. So, before we investigate the case of Titanic, let's first understand..

What is ductile to brittle transition?

Ductile to brittle transition (DBT) occurs when a material that is ductile at room temperature becomes brittle at low temperatures. Brittle materials have a low degree of ductility and will fracture with little or no plastic deformation.

This transition occurs when the transition temperature, which is the temperature at which this transition occurs, is reached. The transition temperature is affected by a variety of parameters such as the composition of the material, the forming temperature, the chemical environment, and the loading conditions.

The transition temperature is usually lower than the melting point of the material. 

What happened in 1912?

On April 15th, 1912, the RMS Titanic was travelling through the North Atlantic on its maiden voyage when it struck an iceberg. The impact of the collision caused a too-long fracture in the lower compartments of the ship, leading to its rapid sinking.

At the time of the disaster, it was believed that the hull of the Titanic had been constructed from steel that was too weak to survive the impact of the collision. However, new research has revealed that the steel used in the ship likely had the necessary strength, but that low temperatures caused the steel to become brittle, which led to its failure.

The transition temperature was likely reached during the cold night, and this caused the steel to become brittle and fracture.

In modern times DBT is still an issue that engineers must be aware of. Steel and other metals will become brittle at low temperatures unless certain precautions are taken.

For example, elements such as nickel are added to steel to raise its transition temperature, and the material is usually preheated before forming in order to decrease its sensitivity to cold temperatures. Today, there are also materials available that are designed to be more resistant to DBT. 

To wrap things up ..

Modern materials that are designed to be resistant to DBT are available, and these should be used in applications where ductility at low temperatures is critical.

Taking precautions to prevent DBT and recognizing that not all materials are equally resistant to this transition, are essential for engineers who are designing structures and components that need to withstand extreme temperatures.