How to process stainless steel pipe?

The use of stainless steel pipes on the market is also very large, and there are many points about its processing technology that we need to understand. The use of stainless steel pipe JBLsteel company is also roughly clear. Let's first talk about the processing technology of stainless steel pipes.

1. Cold drawn (rolled) stainless steel pipe:

The rolling method of cold-drawn (rolled) stainless steel pipe is more complicated than that of hot-rolled (extruded) stainless steel pipe. The first three steps of their production process are basically the same. The difference is that starting from the fourth step, after the round tube blank is hollowed out, the head must be removed and annealed. After annealing, a special acidic liquid should be used for pickling. After pickling, apply oil. Then after several cold drawing (cold rolling), the tube is billet, and special heat treatment. It will straighten after heat treatment.

2. Hot rolling (extruded stainless steel tube):

The raw material of rolled stainless steel pipe is a round tube blank, which is cut by a cutting machine and processed into a blank about 1 meter long, and then sent to the furnace with a conveyor belt for heating. The billet is heated in the furnace at a temperature of about 1200 degrees Celsius. The fuel is hydrogen or acetylene. The temperature control in the furnace is the key problem. After the round tube billet is released, it needs to be perforated by a pressure punch. The common piercing machine is the conical roll piercing machine, which has the advantages of high production efficiency, good product quality, large aperture expansion, and can wear various kinds of steel. After the perforation, the round tube blank is successively rolled by three rollers, continuous rolling or extrusion. After extrusion, the pipe should be removed for sizing. The sizing machine rotates at high speed into the billet through the conical drill to punch holes and form steel pipes. The inner diameter of the steel pipe is determined by the length of the outer diameter of the caliper drill bit. After sizing the steel pipe, it enters the cooling tower and is cooled by spraying water. After cooling, the steel pipe will be straightened. After the steel pipe is straightened, it is sent to the metal flaw detector (or hydraulic test) for internal flaw detection. If the steel pipe has cracks, bubbles and other problems, it will be detected. After quality inspection, the steel pipe must be strictly hand-selected.

After the production of stainless steel pipe is completed, it needs to go through a variety of tests, of which tensile test and hardness test are two very common tests. So what exactly is going on?

Tensile test is to make stainless steel pipe into a sample, break the sample on the tensile test machine, and then measure one or several mechanical properties. Usually only tensile strength, yield strength, elongation at break and area shrinkage are measured. Tensile test is a basic test method for mechanical properties of metal materials. Almost all metal materials, as long as there are requirements for mechanical properties, have specified tensile tests. Especially for materials whose shape is not conducive to hardness testing, tensile testing is one of the means to test mechanical properties.