Re: [MW:21682] Re: forming head

Hi!

Did you check the hardness of Weld and HAZ before Forming? If it is high needs PWHT

ii) Did you flush the weld seam before forming ? It needs to be flush ground as extra reinforcement causing stress concentration during pressing

iii)Did you had any NDT like LPT,UT/RT before pressing

Regards

Hegde

On Saturday, 23 August 2014 9:11 PM, Gopalakrishnan G <gopal2408@gmail.com> wrote:

hi sir

I have welded dish of 25 mm thick using SMAW (E-7018-1) . Hair cracks are observed after forming along the weld toe.

production weld test coupon has been cleared with impact.

Material : SA 516 Gr 70

Thickness : 25 mm

Process : SMAW

Electrode : E-7018 - 1

Code : ASME Sec 8

Please guide the method for forming.

On Sunday, October 24, 2010 5:39:56 PM UTC+5:30, Prakash Hegde wrote:

As such there should not be problem of crack during formimg for SA 516 gr 70 material

However

i)what is the thickness of D/E if it is up to 40mm no need of intermidiate normalising or stress relieving  but higher thk D/E require intermidiate SR

ii) Forming  should be carried step wise and require slowl increase the applied force force(point pressing)

 

regards

 

Hegde

 

From: israr <ahmedi...@gmail.com>
To: Materials & Welding <material...@ googlegroups.com>
Sent: Sat, 23 October, 2010 9:18:33 PM
Subject: [MW:7747] Re: forming head

Dear Mr.
Could you provide me the thickness which you are forming? What type of
the dish head. and what is the process?

If thckness is more calculate the fiber elongation and accordignly
intermediate heat treatment is required.

Regards
Israr Ahmed
Tata Projects Ltd.
India


On Oct 16, 5:09 pm, Navid Navidi <navid_751...@yahoo.com> wrote:
> Hello All,
> We are going to form a head for a presser vessel. Its diameter is about 3000mm.
> And it is made of A516Grade70. Unfortunately, while forming we have cracks on
> the material which cause rejection of the head.
> How can we form a crack-free head? Do we have to do the forming in several
> steps? Do we need heat treatment between forming steps?
> Thank you,
> Saied

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