SS410 overlay with lower hardness

[Vadivel Mahadevan]

Dear gentlemen,

 

I am in a valve industry , and as per API 600 Trim 1 Gate valves,  SS410 overlay on sealing area should have a differential hardness of about 50 HRC.

In my company , we have Sub merged Arc Welding process for doing this overlay on carbon steel base (usually ASTM A216 Gr.WCB)

 

We have being trying a lot with various manufacturers of Wire and flux, but still couldnt achieve this.

 

The wire we use is AWS 5.9 ER 430 and flux is basic agglormorated.

We receive a hardness of about 38 - 40HRC. Our design has given hardness requirement for Gate as 25 to 30 HRC and for seat rings as 35 to 40 HRC to maintain differential hardness at any situation.

I am able to meet seat ring requirement, but not in the Gate.

If I use ER410 wire, then chromium content dilutes to 8 to 9 instead of 11.5 to 13.5

 

Tempering cannot be done as we dont have facility. Facility is at very far distance and it will add cost..

 

It is we grateful if I get a solution for this.

With regards

Vadivel .M

[c sridhar]

ER410 wire, then chromium content dilutes to 8 to 9 instead of 11.5 to 13.5

U hve not mentioned about no. of layers u hve welded.

ER 410 with a single layer welding will have around 9 Cr as mentioned by you.

The same wire will provide req. 13 Cr. with a 3 layer deposit. or 11.5 Cr with 2 layer deposit.

Pl. check on a mock up and if required machine out extra metal on base to maintain the chemistry,

U can deposit one buffer  layer with ER 308, reduce the dilution and achieve 12 to 13 Cr with 

single final layer also.

 

 

 C Sridhar.
 

---

 

---

From: Vadivel Mahadevan <vadivel...@gmail.com>
To: material...@googlegroups.com
Sent: Monday, 2 June 2014 12:45 PM
Subject: [MW:20950] SS410 overlay with lower hardness

--
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/d/optout.

[C.Muni]

Mr.Vadivel ,
It may not be 50 HRC Difference.

--

[Vadivel Mahadevan]

Sorry sir, It is 50BHN..

[Vadivel Mahadevan]

Hi sir,

Thanks for your suggestion.

I am doing single layer weld only ,as the final machined weld deposition height is only 2mm. There is a machining operation after weld , which is upto 2mm.

As suggested by you , I will take trial with buffer layer ER308.

 

Regards

Vadivel. M

[Ramin Kondori]

Dear Vadivel:

First, I believe you meant min of 5 HRC Difference, am I right...?!!!

second, I think tempering is the best solution. Check your spec, do you have NACE requirements...?

You may have to go for PWHT (tempering) anyway (I would do that).

But for dilution problem, have you tried Pulsed MIG...?

Best Regards

Ramin Kondori

Sr. QA/QC engineer

Yadavaran Oilfield Project

SIPC (SINOPEC)

[Vadivel Mahadevan]

Dear sir,

Yes it is 5 HRc, typing mistake.

It is not a NACE requirement, but API 600 standard requirement which is meant for Gate valves.

We dont have PWHT facility nearby our company. It is 150kms away.

Pulsed MIG, which wire shall I use sir?

 

Regards

Vadivel. M

[c sridhar]

Pl.post us the results if  done 

 

Regards,
C Sridhar.
Technical Adviser - Welding,
for Alsta Pristine Engineering Private Limited,.
(A venture of Advance Eng. & Inspection Services). Bengaluru,

Mobile nos: 0 94449 71097, 0 7406 326326, 0 94445 21267.

---

 

---

From: Vadivel Mahadevan <vadivel...@gmail.com>
To: material...@googlegroups.com

Cc: sridh...@yahoo.com
Sent: Tuesday, 3 June 2014 9:04 AM
Subject: Re: [MW:20961] SS410 overlay with lower hardness

[Ramin Kondori]

Dear Vadivel:

There are a few issues that makes it difficult without PWHT. Please read the following:

1. You have to achieve your overlay in only one layer - You do not have many options; you need minimum dilution which is achievable with Pulsed MIG (I'm afraid it's your only option if it is a one layer overlay). You shall use Ar + 1% O2 (first choice) or Ar + 2% CO2 (second choice) for shielding gas. 0.8mm wire and 100-150 (A) for current and 22-27 (V) voltage. As for the arc characteristics, off-time (in each cycle) shall be set at max and background current at mini in order to reduce heat input and hence, dilution.
   
2. You cannot deviate from SS410 chemical analysis requirements - Considering above issue, you have limited options here; ER430 is my recommendation since it has 16% Cr and with one layer of Pulsed MIG (if proper adjustments to pulsed-arc parameters are made) Cr content will be in 11.5-13.5% range. If you go for 410, hardness will be high and you cannot meet chemical analysis requirements either.
   
3. You need a relatively low Hardness (25-30 HRC) - To achieve 25-30 HRC, normally you have to go for PWHT and that is true... BUT if you use pre-heat of 200-250 C (or more) and somehow use some kind of post-heating, chances are you get close to (or even meet) 25-30 HRC requirement. It is not guaranteed but is worth trying. 
   

If I were in your shoes, I would talk with my manager and insist on PWHT. Do not try what I suggested in (3) above. It may not work and you will be frustrated. Insist on PWHT. Of course, measure hardness in as-welded condition and if it is close to 25-30 range, you may get what you want by adjusting pre-heat. If it is not close to that range, PWHT is your only reasonable choice. 

Best Regards

Ramin Kondori

Sr. QA/QC engineer

Yadavaran Oilfield Project

SIPC (SINOPEC)

[Vadivel Mahadevan]

Sir,

I will sure post the result.

I have spoken to my manager on this and I am in the process of procuring the wire - ER308 & ER410.

Once I receive , I will post

 

Regards

Vadivel.M

[kannayeram gnanapandithan]

use half bead technique to achieve this

THANKS & BEST REGARDS

KG.PANDITHAN, AWS-CWI, CSWIP 3.1

CONSULTANT-WELDING & QUALITY

[Vadivel Mahadevan]

Sir,

Can you please explain what is Half bead technique.

I am new to this welding field and have limited knowledge in this.

I have searched in google about this technique but unable to understand exactly what it is..

 

Regards

Vadivel. M