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Essential condition for sanitary pipe fitting oxygen cutting

Stainless steel sanitary pipe fittings prerequisite for oxygen cutting.
Because of the oxygen cutting is mirror sanitary stainless steel pipe fittings oxidation process, not a melting process.Therefore, the precision cutting process in stainless steel tube was cut stainless steel pipe with the following conditions:
1, mirror sanitary stainless steel tube ignition point must be below the melting point:This is gas cutting process can be carried out as normal and the most basic conditions.If light precision stainless steel tube below its melting point, the precision stainless steel tube will be the first to melt when preheating, temperature no longer increases, so will not occur under the action of a cutting oxygen burning process.Pure iron, mild steel, and alloy elements less low carbon alloy steel, can satisfy this condition, thus has good cutting performance.And with the increase of carbon content, steel drop melting point, ignition point, such as the carbon content of 0.70% high carbon steel, the basic equal to its melting point and burning point, so the carbon content is greater than or equal to 0.70% of the steel, use gas cutting was more difficult.Aluminum, copper, iron materials such as the ignition point higher than the melting point, old can't use normal oxygen cutting method for cutting.
2, mirror sanitary stainless steel pipe oxide melting point is lower than the melting point of precision stainless steel tube and liquidOnly in this way, the oxide slag liquid liquid can be blown off, the cutting process to continue.Otherwise, high melting point of the oxide will with solid cover the incision, hinder the oxidation of the material, the cutting process is difficult.Such as high precision chrome steel, chromium nickel stainless steel tube, aluminium and aluminium alloy melting point of material, such as the oxide were higher than the melting point of material itself, and therefore cannot use oxygen cutting method for cutting.
3, mirror sanitary stainless steel tube burns should be exothermic reactionOnly burns out enough heat to preheating of the lower precision stainless steel tube, gives off heat, the more the preheating function, the greater the cutting process is more conducive to smoothly.Mild steel cutting, precision stainless steel tube, released by burning heat accounts for about 70% of the preheating heat, and the heat preheating flames supply accounts for only about 30%.
4, the precision is lower the thermal conductivity of the stainless steel pipeIf the thermal conductivity of the cut mirror sanitary stainless steel pipe is very high, the preheating flames and mirror sanitary stainless steel tube combustion heat supply will soon to precision loss inside stainless steel tube, the temperature fell sharply and the incision short of ignition point, cutting process is difficult to start or stop.Cutting hardening tendency of high carbon steel and high strength level low alloy steel, to prevent the formation of incision or cracks of the hardening layer, should be appropriately increasing preheat flame duty, slow cutting speed, proper preheat when necessary.
5, mirror of sanitary stainless steel tube will hinder the flame cutting process and improve steel hardenability of impuritiesMirror sanitary stainless steel tube blocking gas cutting process impurities such as carbon, chromium, and less silicon and other elements, and at the same time improve the stainless steel hardenability of less impurity elements such as tungsten, molybdenum, in order to ensure the normal order of the gas cutting.When carbon content is greater than 1-1.2% can't normal cut cut pieces.


Sanitary pipe fitting forming process
Sanitary fittings forming hole diameter is less than reducer big end diameter of the tube billet, used in die forming along the tube billet diameter hole enlargement.Hole enlargement technology mainly to solve the reducer in the variable diameter is larger not easily by reducing forming, sometimes according to the requirements of the materials and products forming, expanding and reducing method of combination.Sanitary fittings in the process of reducing or expanding deformation, and variable diameter according to different materials, and determine the concentric reducer adopts cold or hot.Under normal circumstances, as far as possible by cold pressing, but the multiple variable diameter and cause serious work hardening of the thick or alloy steel, wall thickness of materials appropriate USES hot pressing.Reducing sanitary fittings in the pressure pipeline system is an important part of a common, but the research of the basic problems of reducer is still blank.