General structural steel
Structural steels usually find their application according to their tensile strength and yield point. Within a given set of tensile properties, we offer different grades according to our customers’ demands on e.g. fracture toughness, weldability, and chemical composition.
Heat treatable steel
Heat treatable steels gain their application properties through the process of austenitization, quenching and tempering. In a quenched and tempered condition, heat treatable steels have a minimum range of tensile strength of approx. 470 – 1250 N/mm². Besides a good tensile strength, heat treatable steels also possess a high yield strength and ductility. The properties of the end product should be as homogeneous as possible over the entire cross section. High-grade steels do not only have lower phosphorus and sulfur contents than quality steels, but also more consistent properties, e.g. after heat treatment.
Case hardening steel
Case hardening steels are usually steels with low carbon contents, intended for carburisation or carbonitriding, followed by hardening. After hardening, case hardening steels exhibit a surface layer with a high level of hardness and a tough core. The resulting property gradients correspond to the varying stresses and strains imposed on the final parts. The most important steel parameter to be considered is hardenability which is influenced by the chemical composition. In this respect we also distinguish between quality steel and highgrade steel.
The demand for automated machining has led to the development of free-cutting steels Good machinability and chip breaking properties are usually achieved by alloying with sulfur, manganese, lead, tellurium and bismuth. Depending on the material requirements steels are classified into soft free cutting steels, free-cutting case hardening steels and free cutting heat treatable steels - the latter with lower phosphorous and sulfur contents.
Steel with improved cold forming properties
For this purpose, steels with a low yield stress, low hardening during cold forming, and a high deformability are required. Besides these characteristics, these steels should be free of internal and external defects, in order to provide an optimal cold heading product. Depending on the steel grade, a special annealing treatment adapted to the deformation method can be applied to achieve lower final tensile properties. Specialty product: Swissbain-7MnB8
Micro-alloyed steels exploit the strengthening effect of adding micro-alloying elements, such as vanadium, titanium, niobium and aluminium. Ranging from 10-² to some 10-¹ weight %, these elements form precipitates within the steel matrix, which have an influence both on preheating and forming and on the microstructural transformation of the steel.
Besides strength, brittle fracture resistance and ductility are dominant factors for chain steels. Furthermore, aging and wear resistance, weldability, cold shearing properties and cold formability are very important. The weldability requirement limits the carbon content to about 0.25 %. To enhance the strength with such a low carbon content, manganese, chrome, nickel, and molybdenum are alloyed, resulting in strengths of up to 1500 N/mm² in the chain. Aluminium is alloyed for better aging resistance and grain refinement. Good ductility is achieved by a lowest possible content of accompanying elements, such as phosphorus and sulfur.
Construction / Mining
Swiss Steel AG develops and produces special products for construction and mining applications. Our latest developments include the corrosion resistant reinforcing steel Top12, the micro-alloyed reinforcing steel for enhanced static requirements Top700, and the thread bar St900/1100.
The reinforcing steel Top12 is suitable for constructional elements exposed to splash water and stationary water (use of defrosting salt) and for areas susceptible to carbonatisation.
Top12 presents a reliable and economic solution for improving the corrosion resistance of reinforced concrete significantly and thus extending its lifetime. Top12 can be projected and handled according to the methods developed for black rebars, without requiring any special treatment on the construction site .
Top700 is a new micro-alloyed reinforcing steel exhibiting a yield stress exceeding 700 N/mm². The steel therefore meets high static requirements and opens up new options in reinforced concrete construction.
St900/1100 thread bars exhibit a yield stress exceeding 900 N/mm² and feature as-rolled screwable ribs.
All products meet the relevant standards and are being monitored by independent certifying bodies.