The hot rolled, hot extruded a煙數nd cold drawn (rolled) sta低還inless steel pipes are 算知divided according to 店內the rolling method.
According to the metal行師lographic structure of stainless stee放路l, the stainless steel s刀票eamless pipes, ma用呢rtensitic stainless steel seamless pip民街es, austenitic stainless 裡紙steel seamle放一ss pipes, austenitic ferritic stainle購來ss steel seamless pipes a遠樹nd so on are divided into half ferri農商te half martensitic system, stai習船nless steel seaml務水ess pipe, martensitic stainless steel s家看eamless pipe, austenitic st器會ainless steel sea唱下mless pipe an城我d austenitic ferrite stainless s飛呢teel seamless pipe.
Specification and appearance qualit街綠y
A, according to GB14975關器-2002 "stainless steel seam現綠less steel pipe", t著腦he steel pipe is usually 1.5 ~ 10m h路河ot rolled steel tub水民e, and the hot extruded steel pipe is請朋 equal to and greater 票畫than 1m. The wall thickness of the 身頻cold drawn (roll遠煙ed) steel tube is 0.5 to 1.0mm答器, 1 to 7m, and the wal外金l thickness is more than 1.0mm, a船現nd 1.5 to 8m.
The diameter of B and hot rolled (ho視道t extruded) steel t要年ubes is 54 to 480mm i木相n diameter, and 36 kinds of wall thickn日她ess are from 4.5 to 45mm. Th電日e diameter of the c有購old drawn (rolled) steel pip上愛e is 6 to 200mm in total, an音商d the thickness of the wall is fro業知m 0.5 to 21mm, with a tota土月l of 39 kinds.
C, inside and outside s體街urfaces of steel pipes mus員那t not be cracked,輛時 folded, crac城唱ked, cracked, r好術olled, separated and 麗兵scarred. These defects should be comple綠吧tely removed (except 多我for mechanical proce西木ssing pipes). After clea坐熱ning, wall thickness and outer diam習影eter should not exceed t作作he negative deviation. Other minor su樹算rface defects that do not exceed 從線the allowable neg術這ative deviation can not be re作靜moved.
D and straight channel allow depth腦綠. Hot rolled and ho媽美t extruded st你人eel tubes, with di電爸ameters less than or equal to 14路場0mm, are not large化多r than 5% of the nominal wall 和數thickness, the maximum 物街depth is not grea看購ter than 0.5mm, 男些and the cold drawn (rolled) ste現東el pipe is n校船o more than 4% of t唱裡he nominal wall thickness, and the max兵綠imum depth is not greater 用朋than 0.3mm.
E, the end of the匠為 steel pipe sho書服uld be cut into right刀音 angle, and clear the b我得urr.
Manufacturing process of stainless st還刀eel seamless tube
1., hot rolling (e嗎金xtruded seamles湖事s steel pipe唱關): round tube bille紅公t, heating, piercing, three roll s得影kew rolling, cont區請inuous rolling 地生or extrusion, tube drawing, sizing 地店and reducing, cooling to straightening的個, water pressure test (or flaw 商的detection), marking, storage.
The raw material長理 for rolling seamles離高s pipe is round tube billet, a內他nd the round tube 行裡embryo should be cut by cut劇音ting machine to grow 妹醫billets with a height of about近那 1 meters, and transported to 子來the furnace by conveyo姐歌r belt. The bill讀裡et was heated in the 輛道furnace, with a temperature 路化of about 1200 degr藍嗎ees centigrade. Fuel is光場 hydrogen or acetylene. The temper靜小ature control in th術物e furnace is a key problem. The cir媽文cular tube must be piercing化務 through the pre美知ssure piercer after the furnace is disc大窗harged. Gene男就rally more common perforator is 大可a cone roll piercer. This pierc城在er has high production 影船efficiency, good product qua微的lity, large perforation and短什 large diameter, and ca用算n wear a variety of steel. 樹討After the perforatio個讀n, the round tube billet was r朋子olled, rolled or extruded by t問機hree rolls. After extrusion t人土o remove pipe sizing站黑. The sizing machine rotates冷如 into the steel 區請embryo through the co草拍ne bit at high speed 可火and forms the steel tube. The 麗高inner diameter of the steel p拍厭ipe is determined by 熱音the diameter of the diameter of t中那he drill bit.海店 After the steel p報動ipe is fixed, it enters the 西關cooling tower and cooling thro費美ugh the water. After cooling the stee如答l pipe, it will be straightened. The爸房 steel pipe is straight體多ened and sent from th爸機e conveyor belt to the metal flaw de愛不tector (or wate吧街r pressure test) for interna飛路l flaw detection. If there are cracks員間 and bubbles inside the ste月報el pipe, it will be detected海上. After the steel pipe quality inspec鐘海tion, it must be ca話紙refully selected b農請y hand. After the qu什河ality inspection of the steel 很國pipe, the number視白, specification and batch number of 腦我the paint are s制暗prayed with paint. And the crane is hoi做他sted into the ware司大house.
2., cold drawn (rolled) seamless s綠票teel tube: round tube b草吃illet, heating, piercing, hea體錯ding to annealing, acid washing, oil妹西 painting (copper pl票飛ating), multi pass師答 cold drawing (Leng Zh黑愛a), tube to heat treatment, str玩也aightening, water pressure test, i暗還nspection, marking,黃河 storage.
The rolling meth門農od of cold drawn (rolling) s些下eamless steel pipe is風舞 more complicated than that of h機報ot rolling (extruded seamles花地s steel pipe). The first three s林雪teps of their production process 車睡are basically the same. The difference行都 is started fr通體om fourth steps, and the rou兵新nd tube blank will be老信 hit and annealed. After annealing, 少畫a special acid liquid should be use電開d for pickli紙友ng. After pickl作算ing, oil. Then it was followed b匠錢y a multipass cold - drawing (Leng Zha為相) re tube, a sp車高ecial heat treatment. After hea線是t treatment, it is to be stra呢答ightened.