Material Spec Number

Date 05-15-2013 21:51

On the other hand Al, neither group must of necessity be under trained nor stupid, only, LAZY. The one doesn't want to make the effort to make an understandable/applicable WPS and the other doesn't have the initiative, and sometimes the availability, to look up the material. There must be a copy of D1.1 and/or B2.1 available to the shop floor personnel. How many shops have that?

It also means the management may need to create more than one WPS; again- LAZY.

But, I do agree, many don't properly train employees. Takes away too much production time.

Then again, those lists, even the group numbers in D1.1 Table 3.1 are too long for many people to have committed to memory even if trained. So, they still need a copy of the code. But they would probably just let it get burned up or tear out the pages when they needed scrap paper.

Have a Great Day, Brent

By 803056

Date 05-15-2013 22:34

Maybe I missed my mark, i.e., failed to make my point.

The point I was trying to make is that the employer has a responsibility to train their employees. In this case, how to read and apply the WPS. The WPS must be presented in a way that is useful to the welder, not just a bunch of gobbly gook that only the engineer understands.

I have seen problems when working with contractors using WPSs written to meet ASME Section IX where the WPS only listed the P number(s). Unfortunately, the P number is not one of the pieces of information line stamped on a length of pipe or structural shape. John's point is that listing the material group exclusively on a WPS would provide the welder with little useful information. I agree with John that listing the material specification, which is usually found on a length of material is more useful to the welder. However, the employees must understand the importance of the information provided and how it applies to their work. Providing the necessary training is the responsibility of the employer. Many mistakes and costly rework could be avoided if the employer provides the training necessary to ensure the employees understand what they are doing and the ramifications of acting with incomplete information or without understanding the reasons why things are done a certain way.

The employer should be teaching their employees what a material specification is and it is used to differentiate between different materials. Only then will the WPS make sense. I'm sure you have seen instances where the welder, ands yes, even an engineer has substituted one base metal for another because they did not appreciate the differences between two similar materials meeting two different material specifications. An example of this that I have encountered is the difference between ASTM A53 and ASTM A106. I have seen instances where the A53 was substituted for A106 because they were both steel pipe. The difference between the two can be overlooked if either the welder or the engineer/designer doesn't review and understand the material specifications.

The difference between ASTM A36 and A992 or A588 are additional examples. I have seen contractors fabricate structural members from A36 when the drawings indicated A588 was to be used. The problem was one of not recognizing the difference between the material specifications. The mistakes could have been avoided had the individuals involved been properly schooled.

Unfortunately human nature is what it is. Most of us learn what we need to know to get through the day, do our job, and collect a paycheck. It is back to my 10%-80%-10% rule.

There are more cost effective ways of getting the information to the workers on the production floor other than providing copies of the code(s) to each worker. Even if each worker was given a copy of the code, they would still need to be trained how to use them.

Best regards - Al

By eekpod

Date 05-16-2013 16:40

welder2
I don't have my code here with me so I can't look up what your second question is but I want to comment on your first question of just putting group I or group II on the WPS.
Like Al, John and the others commented, yes technically it can be done. My previous employer had it that way when I took over as the QA Manager, then when we started to get into more high end projects (structural buildings, multi story) the EOR 's started to reject them as not specific enough. I would argue that the info that was provided on the WPS was correct (which it was) but still after losing that argument I had to go and revise them. To make it a little easier for myself and to reduce the number of WPS's I had to write I grouped them together.
For example on one WPS I had A36, A992, A572-50,A500 they are all the same group number and that covered 95% of all the base metal we welded. (yes I know there are A36 thickness restrictions and I had that acct for but I don't have the code with me here and now to look it up for this post).
Then I would have a separate WPS for any odd material we may need as needed.
So be careful you may save yourself time now but have to re-do them later.
Good luck

By gastonM (**)

Date 06-13-2013 15:01

Answer 1: I write WPS for my company. I write base metal Group I or group II (see page 3)....... in page 3 I put a list of base metal of each group, and a note with big letters "if the base metal specified in the drawings is not in the list, you cant use this WPS"
Answer 2: hydrogen assisted cracking, may occur if 3 conditions are present: diffusible hydrogen is present at relatively high level, mechanical stresses are present at relatively high level or a hard metallographic structure is pressent (over 350Hv). If you let the stresses, out of discusion, assuming that always are present, you can control hydrogen or hardness. If you dont control hydrogen, only have the chance of control hardness. because of this, a way to stay faraway from hard structures is limit the thickness.