<sub id="r1bj5"><listing id="r1bj5"><meter id="r1bj5"></meter></listing></sub>
<em id="r1bj5"><span id="r1bj5"><track id="r1bj5"></track></span></em><address id="r1bj5"><nobr id="r1bj5"></nobr></address><output id="r1bj5"></output>

      <em id="r1bj5"><span id="r1bj5"><th id="r1bj5"></th></span></em>

          <form id="r1bj5"><form id="r1bj5"></form></form><address id="r1bj5"><listing id="r1bj5"></listing></address>
            <em id="r1bj5"></em>
            WELCOME TO HAOHUA
            Product
            Contact Us

            JIANGSU HAOHUA INDUSTRY GROUP
            Tel: +86-512-58220050
            Fax: +86-512-58810865
            E-mail: sales@haopipe.com
            MSN:    haopipe@hotmail.com
            Skype:  haopipe

            Application
            Loading...

            Precision Seamless Steel Tubes for Automobiles

            Description:

            Jiangsu Haohua Industry Group as one of the leading suppliers in China to supply Precision cold drawn seamless steel tube for Automobiles and Machining Industry etc.
            • Specification
            • Inquiry Now
            Description:

             Precision cold drawn seamless steel tube

            Cold Drawn Seamless tubing (also known as CDS). Cold Drawn Seamless tubes offer tight tolerances compared to Hot Finished Seamless tube, and offers stronger physical properties compared to other mechanical tubing.
            CDS is popular in the hydraulics, being used to make hollowed chrome plated telescopic cylinders and hydraulic rods. It is also popular for large bore, heavy walled, high pressure hydraulic cylinders. Cold Drawn Seamless tubes also find uses in heavy equipment manufacturing such as cranes and garbage trucks.
            General process of cold drawing
            A considerable proportion of the seamless tubes and pipes manufactured through the cold roll piercing technology undergo subsequent cold forming. The principal reasons behind cold drawing are:
            Achievement of closer wall thickness and diameter tolerance
            Improvement in surface finish
            To enhance serviceability
            No premature failure
            Suitable for critical forming Such as 180˚ Bends
            Enhancement of mechanical properties of the tube
            Expansion of product mix towards the lower end of the OD and wall thickness scales.
            THERE ARE THREE BASIC PROCESSES EMPLOYED FOR THE COLD DRAWING OF TUBE:Hollow drawing
            Stationery drawing or floating plug drawing and
            Drawing over a mandrel (also known as drawing on-the-bar)
            Annealing
            After the goods are cold drawn to sizes, the tubes are put on annealing furnace for heat treatment and normalising.
            Straightening
            Post annealing, the goods are passed through a seven roller straightening machine to achieve proper straightening of the tubes.
            Eddy current
            Post straightening, each tube is passed through eddy current machine to detect for surface cracks and other defects . Only the tubes that pass eddy current are fit for delivery to customers.
            Finishing
            Each tube is either oiled with corrosion resistant oil or varnished for surface protection and corrosion resistant as per customers requirement, each tube end is covered by plastic end caps to avoid damage in transit, the marking and specs are put and the goods are ready for dispatch.

             

            Seamless Precision Steel Tubes according to EN 10305-1

            Standard: DIN2391 part 2 , DIN EN10305-1, DIN17175 etc;
            Material: ST35,ST45,ST52.
            Manufacturing method: cold-rolled / cold-drawn
            Delivery condition: BK,BKS,SR,GBK,NBK.

            Certificate
            Factory Certification: 2.2 according to EN
            Acceptance Test Certificate:3.1 according to EN 10204

            Packing:
            in bundles tied with steel strips. External packing by wooden cases if the wall thickness/OD ratio is low.
            Oil-coating is generally necessary especially for export.

            Application:
            Used in hydraulic & pneumatic cylinder ,automobile and other mechanical device .Feature: high precision and high brightness, the inner and outer surface of the tubes have high cleanness without oxid, mechanical properties of the final tubes also come out excellent, promising no leakage under high pressure, no deformation after cold-bent and no cracks when flaring and flattening, ensuring the efficient operation in all service.
            NBK means protective heat-treating under the non-oxidation enviroment to get a bright and smooth surface for the tubes.

            DIN 2391-81 Part 2 Seamless Precision steel tubes(DIN2391-81)
            Standard DIN 2391 defines the technical delivery conditions for seamless precision steel tubes according to DIN 2391 Part 1 which are made from the steel grades listed in section 5.
            Tubes according to this Standard are mainly used where accuracy to dimension and, possibly, small wall thicknesses and good surface condition are required.
            Chemical composition(%)

            Code
            number

            Material number

            Mfg. Process

            C
            max

            Si
            max

            Mn
            max

            P
            max

            S
            max

            St35

            1.0308

            S

            0.17

            0.35

            0.4

            0.05

            0.05

            St45

            1.0408

            S

            0.21

            0.35

            0.4

            0.05

            0.05

            St52

            1.0508

            S

            0.22

            0.55

            1.6

            0.05

            0.05

             

            Mechanical and technological properties

            Code number

            Material number

            Cold-finished hard(BK)

            Cold-finished/soft (BKW) 3)

            Rm(Mpa)

            A(%)

            Rm(Mpa)

            A(%)

            St 35/E235

            1.0308

            480

            6

            420

            10

            St 45

            1.0408

            580

            5

            520

            8

            St 52/E355

            1.0508

            640

            4

            580

            7


            Code number

            Cold finished (soft)(BKW)

            Annealed (GBK)

            Normalized (NBK)

            Rm(Mpa)

            ReH (Mpa)

            A(%)

            Rm(Mpa)

            A(%)

            Rm (Mpa)

            ReH (Mpa)

            A(%)

            St 35/E235

            420

            315

            14

            315

            25

            340-470

            235

            25

            St 45

            520

            375

            12

            390

            21

            440-570

            255

            21

            St 52/E355

            580

            450

            10

            490

            22

            490-630

            355

            22

             

            Note:
            The yield point for the annealed (GBK)condition on delivery is at least 50% of the (ultimate) tensile strength. Depending upon the degree of deformation in the drawing operation, the yield point of tubes delivered in the cold-finished/hard (BK)and cold-finished/soft(BKW) conditions, may be increased to a level close to the tensile strength.
            In calculating the yield point, the following values are recommended : cold-finished/hard condition on delivery ≥ 80% of the tensile strength, cold-finished/soft condition on delivery ≥ 70% of the tensile strength.

            Quality grade
            The tubes are supplied in the following quality grades :
            A) precision steel tubes intended primarily for mechanical stressing, without any particular quality requirement and without acceptance test certificate.
            B) precision steel tubes intended primarily for mechanical stressing, with special quirement and exclusively with acceptance test certificate.
            C) precision steel tubes with special requirement according to section 12. Theses requirements and corresponding tests must be agreed, with the customer having to specify his requirements at the time of enquiry and on ordering.

            Condition on delivery:

            Term

            Symbol

            Explanation

            Cold-finished/hard
            (cold-finished as-drawn)

            BK

            No heat treatment after the last cold-forming process. The tubes 

            therefore have only low deformability.

            Cold-finished/soft
            (lightly cold-worked)

            BKW

            After the last heat treatment there is a light finishing pass (cold drawing) 

            With proper subsequent processing, the tube can be cold-formed (e.g. bent, expanded) within certain limits.

            Annealed

            GBK

            After the final cold-forming process the tubes are annealed in a controlled 

            atmosphere or under vacuum.

            Normalized

            NBK

            The tubes are annealed above the upper transformation point in a 

            controlled atmosphere or under vacuum.

             

            Friendly link: Stainless coils tubing | Titanium Alloy steel pipes | U tubes | Finned tubes | Ferritic Stainless Steel Pipes | Duplex Stainless steel pipes | Austenitic stainless steel pipes | Nickel Alloy steel pipes |
            JIANGSU HAOHUA INDUSTRY GROUP
            Tel: 0086-512-58220050 Fax:0086-512-58810865 E-mail: sales@haopipe.com
            Add: No.17,Southeastern Avenue, Economic Development Zone (South Area),Zhangjiagang City, Jiangsu Province, China.
            Ⱥ