Specifications: diameter: 320 to 127 mm thickness: 0.4 to 12.7 mm Length: 6 m above, and, in accordance with customer demand, supply and other specifications of steel pipe

High pressure pipe fittings: P91 steel pipe welding process

 The choice of 
  P91 steel preheating temperature Ms point of approximately 400 ° C, the preheating temperature 200 to 250 ° C general election. The preheating temperature is not too high, otherwise the connector cooling rate is reduced, may cause the grain boundary carbide precipitation and the formation of the ferrite structure of the welded joint, thereby greatly reducing the impact toughness of the welded joints of steel at room temperature. The lower limit of the preheating temperature can be obtained from the the implant test of Harbin Boiler Factory did a very good description. 

P91 steel pipe
  Bolt test bars using P91 steel, diameter 8 mm deep 0.5 mm, base plate 13CrMo steel, thickness 20 mm, the test without preheating, preheat to 150 ° C preheated 200 ° C preheated 250 ° C conditions. Electrode using J707. Welding current of 165 to 170 A, the arc voltage 21 - 267 V, the test results are shown in Table 2. 
  Table 2 P91 latch test results 
  conditions the sample 
  No. stress level 
  / MPa rupture time 
  / min 
  without preheating 1 303.8 99 
  2 186 8 237 
  3 176.4 8.3 1440 is not broken 
  preheated to 150 ° C 4 421.4 8.1 1260 
  354.8 120 off 
  pre- a heat of 200 ° C for 6 465.2 8.6 1440 is not broken 
  7 482.7   preheated 250 ℃ 9 539 8.2 1440 8.1 438 
  8539 7.9 313   10 600 8.0 1440 
is not broken 
  known by the above test results, without preheating conditions, P91 steel welded joint critical stress to 176.4 MPa; preheated to 150 ° C, the critical stress is 354.8 MPa, 85.4% of the yield limit of 415 MPa for the P91 steel at room temperature; preheated above 200 ° C, the critical stress greater than 460 MPa, more than P91 steel at room temperature to yield limit. Thus, in order to avoid cold cracking is generated when the P91 steel welding, preheating temperature must not be lower than 200 ° C, Germany, the preheating temperature of 180 ° C to 250 ° C, CE provides a preheat temperature of 120 ~ 205 ° C. 
  4.2 interlayer temperature selection 
  layer temperature not lower than the lower limit of the preheating temperature, but as the selection of preheating temperature, interpass temperature is not too high. P91 welding layer temperature is controlled at 200 to 300 ° C. France provides: the layer temperature does not exceed 300 ° C. The provisions of the United States: and interpass temperature located between 170 to 230 ° C.

上一篇:ISO international steel pipe list of standards

下一篇:Wear-resistant pipe type and technical knowledge

 Copyright ©2012 New SindaIf you do not find the information you need, Click Here  Get Support

New Update Pipe List

    API 5CT N80 P110 114.3mm pipe for oil field
    API 5CT N80 P110 114.3mm petroleum casing pipe.

    ASTM A53/ASME SA53 Seamless steel pipe
    ASTM A53/ASME SA53(GR.A/GR.B/GR.C) pipe include:, Black steel pipe,Welded steel pipe, Seamless steel pipe Common: ASTM A53/ASME SA53 Can quickly deliver diverse grades of steel pipes, like A53 Grade.A, A53 Grade.B and other people. Short Introduction ASTM.

    NEWSINDA SEAMLESS STEEL PIPES Products:Boiler and Heat Exchanger TubesPressure Tubes and Line PipeMechanical TubesAutomotive TubesHollows for redraw.

    OCTG Casing Tubing
    OCTG Casing Tubing,Seamless API 5CT casing pipe / tubing / coupling Standard: API 5CT Size: 1.05''-----4-1/2'' Material: H40, J55, K55, N80, L80, P110 etc. Pipe end: EU, NU Length Range: R1, R2, R3 Application: For transportation.
Contact Us Online To Serve You Better

Hot Click PRO

    gas pipelines,Dynamic simulation tools for multiphase oil an
    API5L Oil/gas Pipeline/Spiral Welded Steel Pipe OD: 219.1 mm - 3048mm for conveying water,drainage,coal gas etc. JIS STK steel pipe G3444 G3445
    JIS G3444 STK steel pipe,2.Size:13.7-812mm 3.Material:JIS G3444 STK400/490/500/540/290 .JIS STK steel pipe G3444 G3445. Longitudinal Welded Pipe
    Longitudinal Welded Pipe,Welded steel pipe is steel plate with the bending deformation of round, square and other shapes and then welded into the surface of the pipe joints. Welded steel pipe used is steel or steel billets. We supply of weld. steel pipe mechanical properties
    steel pipe mechanical properties Is to ensure that the steel pipe end-use properties (mechanical properties), an important indicator, it depends on the chemical composition and heat treatment of steel pipe system. Steel pipe standards, depen.