Hardened and Tempered Strip Steel
Hardened and tempered strip steel is the basis of many engineering components and tools. It achieves its strength through a specific heating and cooling process.
This is performed in continuous-line, state of the art heat treating furnaces at voestalpine Precision Strip WI in Pleasant Priarie. This enables us to produce high-strength carbon spring strip with very accurate tolerances for geometry and mechanical properties.
Strength
Cold rolled strip steel has a wide range of possible tempers, from fully hard (fully quenched) through dead soft. This is a result of a thermal treatment process which strengthens the metal by raising the temperature above the critical transformation point and then cooling rapidly through quenching. The strip in this condition is extremely hard but also very brittle, as a result it requires tempering to develop the ductility and shock resistance that users demand.
Tempering is a post-quenching treatment in which the strip is reheated to lower temperatures and held at that temperature for a specific period of time. This reheating is performed in an inert atmosphere to avoid oxidation and to ensure the proper tempering conditions are achieved. The resulting material is more ductile than the original hard martensite and has excellent toughness.
This material is used in a wide range of industrial and automotive applications, including tools like pliers and wrenches that need to withstand high pressures during use. It is also used in clockwork mechanisms and other mechanical applications that require precision and reliability. In addition, the hardness and strength of this strip make it an ideal material for manufacturing springs. This type of steel is available in a wide variety of dimensions, thicknesses and grades to meet the needs of all types of industry.
Toughness
Toughness refers to the resistance of a material to fracture. Toughness generally increases as strength decreases. Depending on the application, it is important for the strip to have both high toughness and low brittleness, especially when subjected to impact loads.
The hardening and tempering processes are designed to provide a balance of these mechanical properties. To achieve this, the steel is heated to hardened and tempered strip steel a very high temperature and then quickly cooled to transform the austenite into martensite, which is a very hard phase but also highly brittle. The second furnace in the production line reheats the strip to a lower temperature and tempers it, which reduces the hardness of the martensite while increasing its toughness.
Depending on the grade of hardened and tempered strip steel, the edges can be slitted, rounded or dressed. This is often required where the edges of the strip will be exposed, particularly where handling safety may be an issue or where the sheared edge could damage coverings such as those used on prosthetic limbs. The surface finish of the strip can also be controlled and can vary from a natural grey, to a polished or blued finish. This is done by careful control of the atmospheres in the furnaces during the heat treatment process and also by adjustment of the heating and cooling rates.
Durability
Hardened and tempered strip steels are used in critical engineering components for their high strength, toughness and resilience. They are also known as spring steels for their ability to return to their original shape after significant bending or twisting. Mead Metals offers a variety of tempering levels to provide the precise mechanical properties required by end users.
Tempered strip steel has been heated to Annealed Steel Strip temperatures below its melting point and then rapidly cooled – a process called quenching. This increases the strength, hardness and toughness of the metal, but also reduces its elasticity.
We offer a range of C80 and EN-42 tempered strip with varying degrees of hardness. Our hardening and tempering lines are designed to ensure a uniform state of stress throughout the strip, enabling it to meet demanding tolerances on edge camber and flatness and be totally free of ‘waviness’.
Our tempered strip is available with or without shearing and in multiple widths and thicknesses, to suit most applications. It can be produced with a surface that is either furnace blue-grey or bright ground to provide maximum cleanliness for welding, cutting and forming. It can also be edge-dressed, if required, using our highly effective in-line machining process that removes shearing marks and produces rounded edges. This enhances the strip’s performance, makes it easier to machine and improves its machinability.
Performance
Hardened and tempered strip steel is an engineering material with exceptional durability, wear resistance, and strength. It is also insensitive to brittleness, and can withstand repeated stress without degrading. The material is commonly used in the manufacture of tools and components that need to withstand heavy pressure or cutting forces.
The process for hardening and tempering steel is a thermal treatment that involves a controlled heating and cooling process. The steel is heated to above the critical transformation temperature and then cooled rapidly. The rapid cooling can cause the steel to become brittle. The brittleness is reduced by tempering, which involves reheating the steel to a lower temperature and holding it there for a specified amount of time.
We produce a wide range of hardened and tempered spring steel strips in coil form or flattened cut lengths. All of our strip products are manufactured to meet international standards like BS,DIN,ISI. Our hardened and tempered strips have excellent spring properties, uniform hardness and texture and provide good workability. They are ideal for use in applications where precision blanking is required and can rationalize further processing by eliminating the need for post heat treatment distortion and waste. Our hardened and tempered steel strips can be supplied in either a furnace blue-grey or a bright ground finish and in any thickness, width and length you require.
