General Information
Germany (West Germany) Special Steelfactory (GSS) is specialized in the production of stainless steels with various compositions and heat treatments. Their product lines cover various grades, including austenitic, ferritic, martensitic as well as precipitation-hardened steels. All of these steels have been designed to provide exceptional resistance to chemical corrosion, mechanical stress and other industrial applications.
Composition of GSS Steels
GSS stainless steels offer excellent resistance to chemical corrosion and mechanical stresses due to their chemical compositions. Generally, these compositions include chromium, nickel, molybdenum, manganese and other alloying elements. Depending on the grade, the proportions of each of these elements will vary.
The austenitic grades are the most commonly produced and are alloyed with both chromium and nickel. Chromium provides improved corrosion resistance, but also makes the steel susceptible to stress corrosion cracking. Nickel is used for toughness and toughness increases as the nickel content is increased. Molybdenum is also present and contributes to the pitting and crevice corrosion resistance of the steel.
The ferritic grades are also more resistant to corrosion but are not as tough as the austenitic grades. They typically have higher chromium content than the austenitic grades, but not as much nickel. They can also contain aluminium, silicon, copper and molybdenum. The ferritic grades are typically used for applications where temperature resistance is required.
The martensitic grades are harder and more brittle than the ferritic grades and usually have less chromium. They are also typically alloyed with other elements, such as tungsten, vanadium and molybdenum, to increase their resistance to corrosion and wear.
The precipitation-hardened stainless steels are alloys of chromium, molybdenum and nickel that are heat treated to form precipitates that increase the hardness of the steel. Usually, these steels also include other elements, such as manganese, aluminium and silicon, to improve their properties and performance.
Heat Treatment
Heat treatment is a critical step for controlling the properties and performance of GSS stainless steels. Depending on the grade, the steels can be annealed, quenched or tempered. Annealing is a process of heating the steel to a temperature that is above the transformation point, then cooling at a specified rate. This softens the steel and improves its formability. Quenching is a process of rapidly cooling the steel to below the transformation point to produce increased hardness and strength. Tempering is the process of reheating the steel to a temperature below the transformation point and then cooling at a slow rate. This process is used to improve ductility, toughness and fatigue strength.
Conclusion
The GSS stainless steels are specialized materials designed to provide excellent resistance to chemical corrosion and mechanical stress. Their compositions vary depending on the grade, but generally alloys of chromium, nickel, molybdenum, manganese and other elements are present. All of the GSS steels must undergo a heat treatment process to improve their properties and performance in industrial applications.
