Quench & tempered – manufacturing the toughest of steel The famed swordsmiths of ancient Japan were highly revered for the quality of their blades. The leading makers would devote many hours to each weapon, forging and treating the metal with a viewto producing blades that were strong, while retaining their edge in battle. Part of the craft involved quenching and tempering the steel, a process that would give these weapons their desired characteristics. Centuries later, quench and tempered (Q&T) steel continues to play an important role, and not just on the battlefield. What is Q&T Steel? Quench and tempering is a heat treatment process that is applied to a metal or alloy in a solid state, using a series of carefully timed heating and cooling cycles, to produce a set of desired physical properties in the material. The mechanical properties of steel are dependent on chemical composition and the size and distribution of the internal grain structure (microstructure). So, while chemical composition determines the type of steel produced, heat treatment controls the microstructure within the steel. By varying the heat treatment applied to the steel, the grain size, distribution and therefore properties of the steel can be altered to best suit its intended end use. By heating the steel to a predetermined temperature and then rapidly cooling it, a coarse grain structure is promoted, resulting in a lean alloy steel. This typically produces a high hardness quality which is ideal for low impact and high abrasion applications such as mining, earth moving, quarrying, agriculture and minerals processing. Under severe cooling rates (such as rapid quenching in cool water), a very hard and brittle microstructure is produced. In this condition, the steel contains high residual stresses and can be too brittle for some applications. Tempering the quenched steel to a carefully determined temperature and then controlling the cooling rate relieves these residual stresses and improves the ductility and toughness of the steel. This increase in ductility is usually attained at the sacrifice of hardness. More Than Just Steel BlueScope Distribution’s National Product, Processing & Solutions Hub plays a major role in delivering large scale national projects, with in-house capabilities, to assist customers to deliver national projects spanning the defence, infrastructure, renewables, mining, transport and agricultural sectors. Located in Unanderra, TheHub is close to key supply partners such as Bisalloy Steel and BlueScope, as well as other value-add services such as blasting and priming. Taking this unified approach provides customers with the convenience and efficiency of having a single point of contact for their projects, delivering centralised project management and access to top-level technical expertise and advice to ensure a hassle-free experience. Read more about the National product, Processing & Solutions Hub on page 04. Learn More Learn More 28 Product Highlight – Quench & Tempered