1. Annealing Heat the steel to a certain temperature and keep it warm at this temperature, and then slowly cool it to room temperature.

What is bearing steel & carbon steel? Bearing steel: Bearing steel is used in producing ball bearing, roller bearing ring, Bearing steel has high and steady hardness and wear resistance. High elastic limitation.

The ordinary steel pipe, such as tap water pipes, It is usually welded by flat plate bending, you can find a weld above; the diameter is generally thick spiral welded seam. Seamless steel pipe is generally molten molten steel through the annular backlog out after the tensile and other processing technology molding, so there is no weld.

What’s normalization treatment? It is also called NBK. It is one kind of heat treatment to get over stress of steel. It heats the goods under more than 30-50℃ with Ac3 or Accm. Keep the temperature some time, and cool the metal by air, sprinkle, spray or in a draught.

Today I will simply expound what is DIN2391 standard and analyze some detail information in this standard.The DIN2391 that is Germany standard specifies technical delivery conditions and dimensions about cold finished seamless precision steel tubes. Like this tube should have following requirements:

During the rolling process of seamless steel tube, especially precision seamless steel pipe, the pickling process is very important. It can remove the oxide scale and rust on the surface. How does it happen? The method of removing the oxide and rust on the surface of steel by acid is called acid was

There are about 5 ways to remove rust from steel pipes. They are cleaning, pickling, ejecting and rust removing. 1.CleaningThe cleaning method is the use of solvent, emulsion cleaning steel surface, in order to achieve the removal of oil, grease, dust, lubricants and other similar organic compounds,