White Tempered Steel Strip
When metals are heated and cooled they undergo a change in their physical properties. This is called tempering. It can increase toughness and improve machinability of steel.
The invention relates to a continuous method for hardening and tempering of strip material. The method has a last temperature zone where the strip material is heated so that it only reaches the tempering temperature immediately before leaving this temperature zone.
Characteristics
The most important characteristics of this type of steel strip are its toughness and high tensile strength. They are produced using a controlled hardening and tempering process. The process involves heating the strip to a higher temperature, then rapidly cooling it down. The resulting strip is tempered to reduce its brittleness and improve its ductility. This process also produces a good level of fatigue resistance.
The hardening process is conducted by heating the strip to above the line drawing in the iron-carbon diagram, leaving it there for a specified period of time and then cooling it down to the tempering point. The amount of hardness that is produced depends on the type of steel, its size and desired mechanical properties. Tempering times range from a few minutes to a few hours.
A hardened and tempered strip is often used in a number of different applications, the majority being spring-type. They are commonly seen in clutch plate segments, washers, retractor springs and a number of other types of engineering components.
A hardened and tempered strip can be manufactured with sheared edges or it can be edge-dressed before or after the hardening and tempering process. This is usually done in order to improve handling safety or to increase the ability of the strip to retain coverings such as fabrics.
Applications
The manufacturing process of this type of steel strip begins with the selection of the grade and type of iron-based alloy that will be worked. It then undergoes a high degree of heating, followed by rapid cooling. This is called quenching and produces very hard steel, White tempered steel strip but it lacks the ductility required for many applications. The strip is then reheated and cooled again to produce tempered steel, which has both hardness and ductility.
The resulting material is used in many demanding applications, such as springs and saw blades. Waelzholz Brasmetal has a special range of application-optimized grades to meet these needs, including martensitic hardened and tempered steel strip for traditional jigsaws and stone gang saws.
Tempered steel is also a key raw material for many different kinds of components, such as clutch plate segments, washers and retractor springs. These Tinplate steel plate manufacturer products are produced in a wide variety of dimensions, mechanical properties and coil weights.
The quality of the final product can be further enhanced by edge machining, either before or after the hardening and tempering process. The Company has a unique in-line machining system that can effectively remove sheared edges from the strip. This significantly improves the surface condition of the material and also reduces the amount of micro-cracks. The tempering time is also important and can be optimized to achieve the desired final hardness.
Advantages
In applications where a high level of hardness is combined with the required shock resistance properties then tempering is an ideal solution. This is achieved through a continuous heat treatment process on our hardening and tempering lines. During this the strip is heated to temperatures from which, after rapid cooling the steel becomes fully hardened. This is known as martensite hardening and produces a very tough material. However, this is also very brittle and it is during the tempering phase that reheating to lower temperature and holding the strip in this state for a specified period of time results in the brittle material achieving some ductility and impact resistance.
This is a highly controlled process and the exact levels of ductility and toughness can be tailored to specific customer requirements. The hardness and toughness values achieved depend on the steel grade and manufacture, hardening and tempering temperatures used.
The strip edge can be machined to either a round or square profile depending on the application, for example in doctor blades the round profile provides fatigue resistance benefits whilst the square edge is particularly suitable for use as a reference plane. It is also possible to supply a polished strip which can be used in corrosion-resistant applications where surface appearance is important or in industrial sawing applications such as stone gang saws.
Pricing
The price of this metal is based on the quality of the raw material. High-grade steel, for instance, is more expensive than low-grade steel because it contains more iron. It also has more tensile strength, which makes it stronger and more resistant to stress and damage.
Tempered steel strip is often used in automotive parts, agricultural tools, saw blades and traditional clock springs. It can be rolled into sheets and cut to length for use in manufacturing different kinds of industrial products. It is more durable than other metals, which makes it a good choice for heavy machinery and construction projects.
In this process, the steel is heated to very high temperatures and then cooled very quickly. It is then tempered, which gives it a hardness that is higher than the original tempering temperature. The result is that the strip has a very short residence time at the tempering temperature.
This is important because the strip can develop cracks if it spends too long at this temperature. The method also prevents the strip from developing a hardness that is too high for its intended applications. During the tempering process, the strip passes through three temperature zones and receives the required tempering temperature as late as possible, which is right before it leaves the last temperature zone. This means that the strip is preheated to temperatures that are lower than the required tempering temperature before it reaches this tempering zone.
