Skip to main content

Re: [MW:4636] Bolts failure

By Materials & Welding
Mr. Soliman,
 
The easiest test to determine the correct strength properties (and grade) of the bolts is to perform hardness testing on the cross section of the failed bolts.  The average hardness on the cross section can be converted to an approximate value of ultimate tensile strength (UTS).  If your budget allows, you may also perform a chemical analysis and microstructural analysis, which will tell you if your material is correct and in the proper microstructural condition.  Additionaly, you can have the fracture surfaces of the bolts examined with an SEM that can search for failure mechanisms like hydrogen embrittlement but this is getting more expensive.
 
Regards,
 
Jeremy Zibin, PEng

From: Chandra Bhusan Tripathi <cbt@rediffmail.com>
To: Mohamed.Soliman@WorleyParsons.com
Cc: materials-welding@googlegroups.com
Sent: Tue, March 30, 2010 1:40:52 AM
Subject: Re: [MW:4632] Bolts failure

You can send damaged bolt for tensile testings. Sometime the bolts also fails due to over tightening. Please check with the manufacturer for correct tightening torque.

On Tue, 30 Mar 2010 11:38:16 +0530 wrote
>




Dear all ,

Ihavea casefor the bolts and nutGrade 8.8 ,Carbon steel material according to EN 20 898.Those bolts and nuts are failedduring the tightening and some of the nuts are loose .

What tests can becarried out to ensure the soundness of those bolts .

Best Regards
M.S






Hotmail: Free, trusted and rich email service.
Get it now.


--

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.



To unsubscribe from this group, send email to materials-welding+unsubscribegooglegroups.com or reply to this email with the words "REMOVE ME" as the subject.


--

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.



To unsubscribe from this group, send email to materials-welding+unsubscribegooglegroups.com or reply to this email with the words "REMOVE ME" as the subject.



*** WORLEYPARSONS GROUP NOTICE ***
"This email is confidential. If you are not the intended recipient, you must not disclose or use the information contained in it.
If you have received this email in error, please notify us immediately by return email and delete the email and any attachments.
Any personal views or opinions expressed by the writer may not
necessarily reflect the views or opinions of any company in the WorleyParsons Group of Companies."






--
>
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.
>

>
To unsubscribe from this group, send email to materials-welding+unsubscribegooglegroups.com or reply to this email with the words "REMOVE ME" as the subject.
>

--
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.
 
To unsubscribe from this group, send email to materials-welding+unsubscribegooglegroups.com or reply to this email with the words "REMOVE ME" as the subject.

Looking for the perfect gift? Give the gift of Flickr!

Comments

Post a Comment

Popular posts from this blog

Re: [MW:34105] SA266 GR4N 4 Cycle SPWHT

By Materials & Welding
Hi,  You are correct, Minimum refers to the one cycle for which this part will expose until final work shop PWHT. hence mill test certificate shall include this.  Max. SPWHT, refers to additional cycles of heat treatment that are reserved for future repairs during equipment lifetime.  Again, these simulated no. Of cycles shall be specified in MTC.  The idea is we need to make sure that steel mechanical properties are not compromised upon exposure to multiple repairs (i e 4 cycles in your case).  One could say, if steel is subjected to 4 cycles and is ok, then it should by defacto be good for one cycle, yet, this is wrong assumption cause mechanical problems and microstructure of materials varies accordingly based on no. Of cycles for which material will expose. This is apparent in alloy steel and especially for impact test values as an example.  In your case, this forged CS with properties before PWHT can be understood to be " as forged" condition (i.e. Wit...
Post a Comment
Read more

Materails FAQs

By Materials & Welding
Q: What are equivalents for standard Q 235 B (and Q 235 A) for U-channels? (asked by: boris.vielhaber@vait.com) A: DIN Nr. = 2393 T.2, 2394 T.2, EN 10025 W. Nr. DIN 17007 = 1.0038 Design DIN 17006 = RSt 37-2, S235JRG2 (Fe 360 B) Q: What is St DIN 2391 BK material? (asked by: dmcandrews@automaticstamp.com) A: Precision steel tubes, cold-finished/hard. Q: What is C.D.W. Boiler Tube? (asked by: montydude123@yahoo.com) A: Cold Drawn Welded Boiler Tube. Q: WHAT IS W.Nr. 1.4301? PLS TELL US IN EASY LANGUAGUE (asked...
21 comments
Read more

Heat tint (temper) colours on stainless steel surfaces heated in air // Heat tint

By Materials & Welding
Introduction The colour formed when stainless steel is heated, either in a furnace application or in the heat affected zone of welds, is dependent on several factors that are related to the oxidation resistance of the steel. The heat tint or temper colour formed is caused by the progressive thickening of the surface oxide layer and so, as temperature is increased, the colours change.   Oxidation resistance of stainless steels However, there are several factors that affect the degree of colour change and so there is no a single table of colour and temperature that represents all cases. The colours formed can only be used as an indication of the temperature to which the steel has been heated. Factors affecting the heat tint colours formed Steel composition The chromium content is the most important single factor affecting oxidation resistance. The higher the chromium, the more heat resistant the steel and so the development of the heat tint colou...
Post a Comment
Read more