Anti-corrosion steel pipe in the country is mainly used for petroleum, chemical, gas, heat, sewage treatment, water, bridges, steel pipes and other engineering fields.anti-corrosion steel pipe is divided into the following categories:
Anti rust process
Anti-corrosion steel pipe is processed through the preservation process, which can effectively prevent or slow down the process in the transport and use of chemical or electrochemical corrosion reaction of steel pipe.
Anti-corrosion surface treatment process of spiral pipe
Anti-corrosion steel pipe in the country is mainly used for petroleum, chemical, gas, heat, sewage treatment, water, bridges, steel pipes and other engineering fields.anti-corrosion steel pipe is divided into the following categories.
3PE Coating Steel Pipe produce
3PE coating Pipe has three layer PE antisepsis structure: the first layer with epoxy powder (FBE> 100um), the second layer with adhesive (AD), 170 – 250um, the third layer with polyethylene (PE) 2.5 – 3.7mm.
FBE Coating
We can coat ¾” through 30” pipe lengths up to 60’ to meet a variety of specifications.
Pipe internal coating
Using epoxy powder coating is for 30 years of history in a foreign country due to the wide range of sources of raw materials, production methods are simple, cheap, good performance, which do not pollute the environment and long service life, so far it is a good anti-corrosion coatings.
Steel pipe internal stratification
The tube is generally believed that non-metallic inclusions in the steel tube will destroy the continuity and compactness, severe inclusions will lead to appear the steel pipe delamination phenomena.
Another thought is hydrogen induced cracking, namely due to hydrogen accumulation caused by metal steel internal gas pressure is too high, the formation of white spots in the round tube, crack extension occurs in the rolling process, and ultimately form a layered defects. In addition, the stress exceeds the strength of two rolls of plastic rotary piercing uneven deformation can also cause delamination.
the control measures of steel pipe internal stratification are:
1, Improved plastic toughness of tube billet
Improve the cleanliness of molten steel, reducing harmful inclusions; increase the proportion of the slab crystal axis, to reduce the center segregation and center porosity; using reasonable cooling system to avoid cracks appeared in the interior slab; billet or rolling slab to be taken offline slow cooling process, reducing internal stress, thus ensuring the microstructure and mechanical properties of steel billet and finished products meet the technical standards.
2, Reasonable control heating temperature
By measuring thermoplastic curve to choose the best heating temperature. Also note that there is enough heating tube holding time, to reduce the pipe plastic deformation resistance and improve toughness.
3, Reduce the roll speed
Speed is a key parameter roll piercing process, in the roll speed from low to high variations in the process, there is a critical stratification began the roll speed. At lower roll speed, easy to form a tube cavity; higher roll speed, and capillary tube formation of layered defects easily. In order to eliminate delamination defects and capillary tube, roll speed should be reduced to the critical stratification began following the roll speed.
Basic functions of erw pipe coating:
- making the surface of ERW steel pipes free from electrochemical corrosion of the soil medium, the basic physics of bacterial corrosion protection.
- resisting the move of the soil medium creep stress, static stress and abrasion force method and structure of the basic machinery protection.
The basic principles of urban gas pipeline coating selection:
- good insulating and mechanical properties;
- good resistance to cathodic disbondment performance;
- good resistance to water, gas permeability;
- good chemical resistance soaking performance and anti-aging properties;
- resistance to low temperature and high temperature performance;
- easy mending and mending;
- at reasonable prices.
Steel pipe internal stratification
The tube is generally believed that non-metallic inclusions in the steel tube will destroy the continuity and compactness, severe inclusions will lead to appear the steel pipe delamination phenomena.
Another thought is hydrogen induced cracking, namely due to hydrogen accumulation caused by metal steel internal gas pressure is too high, the formation of white spots in the round tube, crack extension occurs in the rolling process, and ultimately form a layered defects. In addition, the stress exceeds the strength of two rolls of plastic rotary piercing uneven deformation can also cause delamination.
the control measures of steel pipe internal stratification are:
1, Improved plastic toughness of tube billet
Improve the cleanliness of molten steel, reducing harmful inclusions; increase the proportion of the slab crystal axis, to reduce the center segregation and center porosity; using reasonable cooling system to avoid cracks appeared in the interior slab; billet or rolling slab to be taken offline slow cooling process, reducing internal stress, thus ensuring the microstructure and mechanical properties of steel billet and finished products meet the technical standards.
2, Reasonable control heating temperature
By measuring thermoplastic curve to choose the best heating temperature. Also note that there is enough heating tube holding time, to reduce the pipe plastic deformation resistance and improve toughness.
3, Reduce the roll speed
Speed is a key parameter roll piercing process, in the roll speed from low to high variations in the process, there is a critical stratification began the roll speed. At lower roll speed, easy to form a tube cavity; higher roll speed, and capillary tube formation of layered defects easily. In order to eliminate delamination defects and capillary tube, roll speed should be reduced to the critical stratification began following the roll speed.