Advantages of Steel that Contribute to Sustainable Society
Steel is an abundant, sustainable material that can be reborn endlessly
Iron is believed to constitute one-third of the Earth’s weight.
Steel is an affordable material and is cheaper than water in a plastic bottle in comparing price per unit weight).
Steel represents 90% or more of metal products, as steel being abundant, cheap, and having good workability, and has a wide range of applications.
Steel is a sustainable material to be reborn in new steel products endlessly
Steel is easily sorted from a mixture with other materials and can be endlessly recycled without causing deterioration in quality — quite a unique characteristic. Steel is a perfect material for recycling as it can be recycled endlessly into all kinds of steel products after the end of its product life.
Diverse properties and a wide range of applications
Due to diverse advantages such as strength and easiness to work, steel has been used in a wide range of applications and deserves recognition as the most outstanding material for the infrastructure of society, a material that supports people’s lives and overall economic development.
Steel is close to us and we cannot live without steel products. Steel is for here for all of us now and will be with us in the future.
Diverse properties that support a wide range of applications
Steel is a material with great potential due, in part, to its having a much higher theoretical strength than other materials.
In addition to adjusting carbon and other content to give a certain steel product specifi c desired characteristics, steel’s properties can be fi nely controlled to meet function and performance requirements, including requirements that did not exist in the past. We do this by controlling the combination of its temperature and rolling at the manufacturing stage or by adding alloys. Further development in steel and its usage will push the potential horizon further outward.
Potential capacity and present application level of material strength
1 Theoretical strength is said to be 1/5 to 1/7.5 of the modulus of rigidity. The above data uses 1/7.5.
2 Gigapascal (GPa) is a unit to measure tensile strength. Giga denotes a factor of one billion (109).
Steel is an outstanding material from the Life Cycle Assessment (LCA) perspective
Let’s consider the overall life cycle
The Life Cycle Assessment method (LCA) is a way of thinking to evaluate environmental impact of a product over its entire life cycle. While many aspects of environmental impact cannot be seen, the LCA is an attempt to visualize the impact over the life cycle of a product, from production of its raw material to use, disposal and recycling of the end product.
From the LCA perspective, steel’s environmental impact can be said to be very low relative to other materials. In order to continue to supply steel as a sustainable material, while taking advantage of its excellent LCA characteristics, we aim to realize carbon neutrality .
Environmental impacts of steel made via the BF and EAF routes, using an LCA approach
The blast furnace (BF) route to reduce iron ore to make steel may appear to generate a higher environmental impact than the method that melts steel scrap in an electric arc furnace (EAF) to make steel. However, the BF route creates steel products that generate scrap that, through recycling, has an effect of CO2 emission reduction. As that scrap recycling effect offsets the CO2 emissions in the BF process, environ-mental impacts of the BF and EAF routes in total terms are the same as steel is repeatedly recycled.
This approach is recognized in the ISO 20915 and the JIS Q 20915 and is becoming a global standard.