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Up Topic Welding Industry / Technical Discussions / Weld breaking C-1010
- - By sraghavan Date 10-14-2005 20:35
We used to normally weld a 304 S/S stud to a pin (C-1008 material). We recently changed the pin material to C-1010. Now we are not able to weld the same stud (304 S/S) to this c-1010 pin. The weld joint does not look good visually and breaks off very easily. We changed all the variables in welding process (dwell time, amps etc) and nothing seems to be working. Has anyone seen this issue before?. I would appreciate your thoughts on why this is happening?

Ps: The new C-1010 pins are from China and material tests confirmed it.

Thanks,
Seth
Parent - By - Date 10-14-2005 20:40
What is your filler metal?
Parent - - By sraghavan Date 10-15-2005 18:44
Tungsten
Parent - - By - Date 10-15-2005 21:41
The C-1010 is a high carbon spring steel and you are using tungsten as your filler material? Are you sure?
Parent - - By billvanderhoof (****) Date 10-17-2005 05:18
Isn't c1010 low carbon?
Bill
Parent - By - Date 10-17-2005 13:18
Bill,
I think it's a high carbon spring steel.

C= 0.08-0.13% (high carbon)
Mn= 0.30-0.60%
P- 0.040% max
S- 0.050% max
Parent - By - Date 10-17-2005 15:38
Bill,
I'm sorry. The carbon content of the C-1010 is such that it is not considered a high carbon. My mistake. According to the AISI specifications, such steels as C1008, C1010, and C1020, etc, refer to the carbon content. The carbon content of these steels do not exceed 0.08, 0.10, and 0.20% respectively.
Parent - - By sraghavan Date 10-17-2005 14:14
Sorry, We don't use any filler material. We have two tungsten tip electrodes (with conical tip) which sustain the arc between them. Still not sure on why weld is breaking.

Thanks all for the help

Seth
Parent - - By - Date 10-17-2005 14:23
Seth,
It's probably due to the high sulfur content causing it to crack and break, especially with no filler added. Using a high strength filler metal will usually help counter the propensity of the cracking possibility due to the sulfur. That sounds to me like what could be the problem.
Parent - - By sraghavan Date 10-17-2005 14:52
Thanks. The configuration of our welding system is not letting us use any filler material in this process.

Can you please think of any other ways other than to use a filler material which can solve this problem?.

Thanks a lot!
Seth
Parent - - By - Date 10-17-2005 15:03
Seth,
Not really..That high of a sulfur content is probably going to give you problems if you don't add a high strength filler metal to counter the effects of the sulfur. High sulfur steels are hard enough to weld even when adding a filler metal, but withour adding a filler metal is a real problem. Again, that is what it sounds like to me. I cannot think of any other reason you are cracking and breaking.
Parent - - By MBSims (****) Date 10-19-2005 03:26
For a low carbon steel, the specified sulfur limit is not excessive for welding. This would be a much bigger problem in stainless steel or nickel alloys, but for mild steels the general rule is to have about 6 times as much manganese as sulfur to tie up the sulfur as MnS. If the material is really C1010, an autogenous weld should be possible.

Material identification and traceability are often problems in commercial grade materials, especially materials from China. When you had the chemical analysis performed to verify it was C1010, what were the actual results? Also, do you have any hardness numbers on the unwelded pins vs. the weld area?


Parent - - By sraghavan Date 10-20-2005 20:40
The hardness values are as below
C-1010 material
A. Rockwell hardness: 87 Rb becomes 90 Rb in Heat affected zone
B. Knoop hardness: 189 and becomes 204 in heat affected zone

C-1008 material
A. Rockwell hardness: 53 Rb becomes 86 Rb in heat affected zone
B. Knoop hardness: 110 becomes 181 in heat affected zone


Parent - - By MBSims (****) Date 10-20-2005 21:33
Hardness is rather high for C1010. It would be expected to be around HRB 60 or HK 123.

The way your post reads, it sounds like you had done some material tests to confirm the material was C1010 (chemical analysis?). What was the actual chemical composition for the C1010 when it was tested for confirmation?
Parent - By jerrykroll (**) Date 10-20-2005 23:01
do a PMI (positive material identification)

I have just seen cast steel parts come in from China that were actually cast iron, and 6061 aluminum that tested as 3003.

Any chance you have some L1010 (leaded free machining steel ) ?
Parent - By vigueur Date 10-22-2005 06:38
I am not sure some heat treatment will benefit or not, maybe the material is not so uniform
Up Topic Welding Industry / Technical Discussions / Weld breaking C-1010

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