Stainless steel can be divided into four types: austenitic, martensitic, ferritic and duplex stainless steel.This is based on the metallurgical organisation of the stainless steel at room temperature. When mild steel is heated to 1550°F, its organisation changes from the ferrite phase at room temperature to the austenite phase. Upon cooling, the mild steel changes back to ferrite. The austenite present at elevated temperatures is non-magnetic and is less strong and tougher than room temperature ferrite.When the Cr content in the steel is greater than 16%, the room temperature ferrite organisation is fixed so that the steel remains ferrite over all temperature ranges. Therefore, called ferritic stainless steel. When the Cr content is greater than 17 per cent and the Ni content is greater than 7 per cent, the austenite phase is fixed so that the austenite state is maintained from low temperatures to almost the melting point of the range.
Flux cored wire is also known as tubular wire or powder cored wire. Surfacing flux-cored wire currently on the market, its cross-section for the ‘O’ shape, the interface for the lap or butt, belongs to the seamless flux-cored wire, the use of powder easy to absorb moisture, affecting the performance of the welding process and the intrinsic quality of the weld, and even in the weld to produce internal weld defects such as porosity.Seamless flux-cored wire has no moisture absorption, good welding quality and other advantages, but the manufacturing process is complex, the market is relatively rare.The advantage of seamless flux-cored wire is that the hydrogen content of the wire itself is very low. This can be achieved:
(1) Moisture (source of hydrogen) adhering to the flux and hull can be reduced by high-temperature dehydrogenation during the wire manufacturing process; (2) Even after the wire has been manufactured, moisture absorption from the atmosphere to the inside of the wire does not occur at all because of the seamless structure of the outer portion without gaps.
Welding consumables for pipeline engineering are primarily used in the construction of pipelines for oil, natural gas, and other industries. These materials must offer excellent
Do you know the welding positions indicated by the following symbols? A, B, C, D, E, F, G, H, J, L 1, 2, 3, 4,
How Inverter Welding Machines Work Inverter welding machines rely on powerful electronic switches to control the flow of electricity. The most common types use IGBT
