Galvanized mild seamless carbon steel square tube

        Seamless steel pipe :

        Seamless steel tube can be divided into hot rolling and cold rolling ( dial ) seamless steel tube .

        Hot rolled seamless steel tubes are divided into general steel tubes , low and medium pressure boiler steel tubes , high pressure boiler steel tubes , alloy steel tubes , stainless steel tubes , petroleum cracking tubes , geological steel tubes and other steel tubes .

        Cold-rolled ( dialed ) seamless steel tubes include general steel tubes ,  low-medium pressure boiler steel tubes , high-pressure boiler steel tubes , alloy steel tubes , stainless steel tubes , petroleum cracking tubes , and other steel tubes , as well as carbon thin-walled steel tubes , alloy thin-walled steel tubes , stainless steel tubes . The external diameter of hot-rolled seamless pipe is generally greater than 32mm , and the wall thickness is 2.5-75mm . The diameter of cold-rolled seamless pipe can be up to 6mm , the wall thickness can be up to 0.25mm , the external diameter of thin-walled pipe can be up to 5mm , and the wall thickness is less than 0.25mm . The cold rolling has higher dimensional accuracy than the hot rolling .

         Generally used seamless steel tube : it is made of 10 , 20 , 30 , 35 , 45 and other high quality carbon-bonded steel 16Mn , 5MnV and other low alloy structural steel or 40Cr , 30CrMnSi , 45Mn2 , 40MnB and other alloy steel hot rolled or cold rolled .Seamless tubes made of low carbon steel such as 10 and 20 are mainly used in fluid conveying pipelines . Seamless tubes made of medium carbon stee l, such as 40Cr , are used to make mechanical parts , such as stressed parts for automobiles and tractors .The general use of seamless steel tube to ensure the strength and flattening test.Hot rolled steel pipe delivered in hot rolled or heat treated condition ; Cold rolling is delivered in heat-treated condition .

        Seamless steel tube for low and medium pressure boilers : used for manufacturing various low and medium pressure boilers , superheated steam pipes , boiling water pipes , water wall pipes and superheated steam pipes , large smoke pipes , small smoke pipes and arch brick pipes for locomotive boilers.Use high quality carbon structural steel hot - rolled or cold - rolled seamless steel tubes . Mainly with 10 , 20 steel manufacturing , in addition to ensure the chemical composition and mechanical properties to do hydraulic test , edge rolling, flaring, flattening and other tests.Hot rolling shall be delivered in hot rolling condition , and cold rolling ( rolling ) shall be delivered in heat treatment condition .

        High-pressure boiler tubes : mainly used in the manufacture of high pressure and over pressure steam boiler pipes , etc . With high quality carbon structural steel , alloy steel and stainless heat resistant steel seamless steel tube , these often under high temperature and high pressure boiler tube , tube in high temperature flue gas and steam will happen under the action of oxidation and corrosion , so the steel pipe with high rupture strength , high oxidation resistance , and have good organizational stability , using steel grade are : high quality carbon structural steel grade 20 g , 20 MNG , 25 MNG;The steel Numbers of alloy structural steel are 15MoG, 20MoG, 12CrMoG, 15CrMoG, 12Cr2MoG, 12CrMoVG, 12Cr3MoVSiTiB , etc . 1Cr18Ni9 , 1Cr18Ni11Nb high pressure boiler tube in common use of rust-resistant steel , in addition to ensure the chemical composition and mechanical properties , to do water pressure test root by root , to do flaming , flattening test .Steel tubes are delivered in heat-treated condition .In addition , the finished steel tube microstructure , grain size , decarbonization layer also has certain requirements .

        Seamless steel pipe for geological drilling and oil drilling : to explore the underground rock structure, groundwater, oil , natural gas and mineral resources , the use of drilling RIGS drilling .Drilling is indispensable for oil and natural gas exploitation . Seamless steel pipe used for oil drilling for geological drilling is the main drilling equipment , mainly including outer core pipe , inner core pipe , casing pipe and drill pipe .Due to the drilling pipe to go deep into the thousands of meters formation depth work , working conditions is very complex , drill pipe under pull , pressure , bending , torsion and uneven impact load stress , but also by mud , rocks and wear , therefore , requires tubing must have sufficient strength , hardness , wear resistance and impact toughness , steel pipe steel with " DZ " pinyin "( geology ) plus number one on behalf of the steel yield point , said common steel grade DZ45 MNB 45 , 50 mn ; DZ50 40Mn2 , 40Mn2Si ; DZ55's 40Mn2Mo, 40MnVB ; DZ60's 40MnMoB and DZ65's 27MnMoVB.All steel tubes are delivered in heat-treated condition .

        Petroleum cracking pipe: seamless pipe used in furnaces , heat exchangers and pipelines in petroleum refineries.Commonly used high quality carbon steel ( 10, 20 ) , alloy steel ( 12CrMo , 15CrMo ) , heat resistant steel          ( 12Cr2Mo , 15Cr5Mo ) , stainless steel ( 1Cr18Ni9 , 1Cr18Ni9Ti ) manufacturing . In addition to the chemical composition and various mechanical properties of the steel pipe , but also to ensure that water pressure , flattening , such as flaring test , and surface quality and non-destructive inspection .Steel tubes to be delivered in heat treated condition .Stainless steel pipe : with a variety of stainless steel hot rolled , cold rolled stainless steel pipe , widely used in petroleum , chemical equipment pipelines and various USES of stainless steel structure parts , in addition to the chemical composition and mechanical properties should be guaranteed , where used to withstand the pressure of the fluid pipe to ensure that the water pressure test qualified . All kinds of special steel pipes shall be guaranteed according to the specified conditions .