| Hi! If design temp is above 320C It is mandatory to have Temper Brittle screen test.(To plot a transition curve to know the shift in Impact value , In such case PQR are to be tested for impact at MDMT and Upper and lower shelf Temp. For this test step cooling heat treatment is essential. Step cooling Cycle as under You require to test Impact after i)Min PWHT cycle say Note 1---Min PWHT –7050C +/-5 soaking time-5Hrs Note 2- Min PWHT cycle + Step cooling treatment cycle shall be i) Heat To 5930C from 3000C @ 40-560C /hr ii) Hold @ 5930C for 1 hr and cool @ max 60C /hr to next temperature. iii) Hold @ 5380C for 15 hrs and cool @ max 60C /hr to next temperature iv) Hold @ 5240C for 24 hrs and cool @ max 60C /hr to next temperature v) Hold @ 4960C for 60 hrs and cool @ max 30C /hr to next temperature vi) Hold @ 4680C for 100 hrs and cool @ max 280C /hr to 315 0C B) Refer ASME Sec VIII Div I Mandatory Appendix 31 , UOP or Cheveron spec Regards Hegde P.B +91 8805593046
--- On Tue, 20/3/12, manpreet <manpreetsin88@rediffmail.com> wrote:
From: manpreet <manpreetsin88@rediffmail.com>
Subject: [MW:13929] Clarification on Step Cooling Test
To: mailmrsiva@yahoo.com
Cc: materials-welding@googlegroups.com
Date: Tuesday, 20 March, 2012, 6:03 AM
Hi, Please have a look at the ASTM A387 spec, Impact properties after Step cooling test is mentioned as "Supplementary Requirements" and should be conducted only if explcitly mentioned in the Client Spec (is it so?) Purpose of test is to simulate the Material's behaviour after prolonged exposure at higher temperature and suspectibility to Temper Embrittlement mentioned in ASTM spec, S62. Therefore it's strongly recommended to raise a query to Client if in doubt, Results over the years has shown that it is an overly conservative requirement, adding additonal cost and extended delivery with no percieved benifit. Pretty sure you would be relaxed with Client's answer to waive this requirement and if not, then we would discuss test in detail, Also note that if Step cooling test is a requirement then Base materials itself should be simulated. Regards Manpreet Singh Dear Experts, We need to make a manifold for heater of size 60" and 40" diameter of P22 material. It has been decided to use A387 plate for making the manifold. 1. Can anyone give details of What is Step Cooling test connected with this material and what are the requirements of the step cooling test relating to qualification of WPS/PQR. 2.Can we use ER90B3 and E9018B3. Also the Joint configuraiton is Double V groove with backgouging as per client requirements. 3.How much length of plate to be used for preparing the PQR to perform the step cooling test. 4. Further, we have a extruded branch connection of size 4", 5" and 6" of material A 335 Gr.P9, thickness around 7.11. What electrode can we use for this purpose? Do we need to perform the same Step cooling test for this WPS/PQR? Kindly suggest. Thanks and regards, Siva -- To post to this group, send email to materials-welding@googlegroups.com To unsubscribe from this group, send email to materials-welding+unsubscribe@googlegroups.com For more options, visit this group's bolg at http://materials-welding.blogspot.com/The views expressed/exchnaged in this group are members personel views and meant for educational purposes only, Users must take their own decisions w.r.t. applicable code/standard/contract documents.
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