Interpass Temperature

[Siva Sailam]

Dear sir,

I know that inert pass temp are to be maintained on 1 layer and subsequent layer, What i want to know is  does inter pass temp are to be maintained on root pass

[Harikrishnan N S]

Hai

For root pass you have to maintain the pre-heat temperature (which is also the minimum allowable inter pass temperature).

Regards

Harikrishnan

[binu valiyaveeedu]

As name implies it is the max temperature which has to be keep between two passes...

Regards,
Binu valiyaveedu

On 6 Aug 2013 07:37, "Siva Sailam" <sivasai...@gmail.com> wrote:

Dear sir,

I know that inert pass temp are to be maintained on 1 layer and subsequent layer, What i want to know is  does inter pass temp are to be maintained on root pass

--
To post to this group, send email to material...@googlegroups.com
To unsubscribe from this group, send email to materials-weld...@googlegroups.com
For more options, visit this group's bolg at http://materials-welding.blogspot.com/
http://www.linkedin.com/groups/MaterialsWelding-122787?home=&gid=122787&trk=anet_ug_hm
 
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.
---
You received this message because you are subscribed to the Google Groups "Materials & Welding" group.
To unsubscribe from this group and stop receiving emails from it, send an email to materials-weld...@googlegroups.com.
For more options, visit https://groups.google.com/groups/opt_out.
 
 

[Octane Mac]

Siva,

Interpass temperature is the maximum temperature above which you should not be making a pass over another. For example, while welding stainless steels, maximum interpass recommended is 150 C (300 F) which indicates that after making a pass, you need to wait till the weld cools down at least to 150 C (300 F) and then start making another weld pass over that.

Octane.

[Ramesh Barot]

Dear Sir,

 

where we should measure it?????

 

On the centre of weld pass, back side or near to heat affected zone???

 

 

 

Thanks,
With Best Regards,
Ramesh Barot

[Pieper QSI]

Dear Sir,

 

Interpass temperature should be measured on the weld metal on the position where the next weld run will be started just before starting the next run. Preheat temperature you should measure on the base metal 50 – 75 mm away from the weld area and in case of large thicknesses also at the opposite site from welding in order to ensure that full thickness have reached the required value.

 

Met vriendelijke groeten / Best Regards,

 

Herman Pieper

QA-QC Inspector / IWI-C Welding Inspector / IWT / Materials Expert

 

Job van der Havestraat 6

8384 DB, Wilhelminaoord

Cell: +31 6 51691215

[Octane Mac]

Adequately explained by Mr. Herman.

Octane

You received this message because you are subscribed to a topic in the Google Groups "Materials & Welding" group.
To unsubscribe from this topic, visit https://groups.google.com/d/topic/materials-welding/AOqEXzZqFlI/unsubscribe.
To unsubscribe from this group and all its topics, send an email to materials-weld...@googlegroups.com.

[Dindo]

does this mean that the minimum interpass temperature is lower than the preheat temperature? If you are taking the interpass temperature at the weld metal, it is safe to say that the temperature away from the weld (50-75mm) would be lower.

[kannayeram gnanapandithan]

In multipass welding, Interpass temp should not be less than Preheat temp

[Octane Mac]

All,

I think we have been confusing this topic.

First of all, interpass temperature is set as maximum limit and not as a minimum (refer to WPS form as per ASME IX). Regarding its minimum value, it depends on the pre-heat temperature. Where a specified pre-heat temperature is applied on a material, interpass must not go below that. Otherwise, you need to apply the heat again to start welding the materials.

Take example of SA-335 Gr. P21 for which a recommended pre-heat of 177 C (350 F) is mentioned in ASME B31.3. This means that you cannot start welding till the material is at this temperature. Now, the maximum interpass temperature for this material is 316 C (600 F), taken from API 582. This means that you should not start welding another pass over the one when the temperature is more than 316 C (600 F). Therefore, in multipass welding of P21, you need to start welding a new pass only when base metal temperature is > 177 C (350 F) and the weld metal < 316 C (600 F)

Octane