Steel structure components are generally manufactured in a factory, including the following processes: lofting, sizing, cutting, edge processing, bending, edging, correction, anticorrosion and finishing, etc.
I. setting out and counting materials
1.1 lofting: the process of drawing the entity of a product or component on a lofting table or platform according to the size and shape required by the construction detail or part drawing of the product at 1:1, in order to obtain the actual length and to make a template. For the more complex shell parts, we still need to do the drawing. Computer-aided design should be adopted when conditions permit
1.2Material: draw a solid sample of the component on the steel according to the sample and mark it with all kinds of processing marks to prepare for the cutting of the steel.
II. Cutting stock:Cutting is usually used to separate the shapes of the parts from the raw materials. There are three main methods: gas cutting, mechanical shearing and isolator cutting. Now let's take a look at it
2.1 Gas cut off: preheated flame produced by a mixture of oxygen and combustible gas heats the surface of the metal to the combustion temperature and causes severe oxidation of the metal, releasing a large amount of heat to cause the lower metal to burn on its own, At the same time, through the high pressure oxygen jet, the oxide is blown away to form a narrow and neat slit. The gas cutting method also includes manual gas cutting, semi-automatic gas cutting and automatic gas cutting. The width of manual gas cutting seam is 4mm, and the width of automatic gas cutting is 3mm. Gas cutting equipment is flexible, low cost, high accuracy, can cut most of the thickness of steel, especially with curve parts or thick steel plate, is the most common cutting method.
2.2 Mechanical shearing and shearing: realized by punching, cutting, friction, etc.
(1) punching shear cutting: when plate thickness is 12mm, shearing machine and combined punching shearing machine are used to cut steel. The cutting speed is fast and efficiency is high, but the cut is rough.
(2）cutting and cutting: cutting steel with bow sawing machine and band saw machine has good precision.
(3) friction cutting: using friction sawing machine and grinding wheel cutting machine to cut steel, the speed is fast, but the cut is not smooth enough, and the noise is bigger.
2.3 Plasma cutting: use high temperature and high speed plasma flame flow to melt and blow off the metal and its oxide at the notch to complete the cutting, can cut any metal, especially the high melting point rust and non-ferrous metal copper, aluminum, etc.