welding of A516 garde 70

Date 03-20-2007 19:43 Edited 03-20-2007 19:53

A-516 Gr 70 is a low carbon, fine grain steel suitable for low temperature service. It's easy to weld with SMAW and MIG.
Mechanical tests usually include bending, tensile and impact (Charpy, as they say in the USA) tests.

The HAZ is roughly divided in three sections:
a) The section adjacent to the weld shows a dentritic microstructure made up of large pearlitic grains on a ferritic fund.
b) The section in the middle shows a ferritic and pearlitic assorted grains of similar size.
c) the section apart from the weld shows small ferritic and pearlitic grains on a fund of larger ferritic grains.
d) the base metal, not affected by heat, remains the same, i.e., assorted pearlite and ferrite grains.

Equipment and consumables cost data you'll find at a welding material distributor in your country (which, by the way, we don't know which is)
Giovanni S. Crisi
Sao Paulo - Brazil

By js55

Date 03-20-2007 19:51

Giovanni is right, there really isn't anything special with this material. In fact, its really good stuff. The only problem I have ever had with this material is comparing HAZ impacts with the BM. The HAZ will degrade, But watching your heat inputs you will still stop a hammer on 240 lb machine at room temp.
Perhaps you can be more specific with the types of problems you are having.

By gautam agarwal Date 03-21-2007 08:23

thank you sir but few more things i want to get clarified:

1. plz explain something abt microstrucure of weld metal also
2. if u ve ne snap shot of microstructure wm, bm and haz then plz do send
3. also tell me which etchant shud i use for micro and macro structure of these
4. and plz comment on hardness of bm, wm and haz with quantitative values
5. how can i calculate the exact length of the haz
6. i ve done impact test at room temp for wm and haz but i dont ve impact values of pm at room temp so how shud i compare or what conclusion shud i draw
7. as per the cost data i need % monthly interest rate and ownership cost for equipment costing
8. last but not the least what shud be the approx deposition rate, deposition efficiency and operating factor of smaw and gmaw welding.

thanking you,
gautam
gautam.lntecc@gmail.com

By gautam agarwal Date 03-22-2007 07:14

hello,

can anyone help me in solving above mentioned issues? i m waiting for ur reply.

thanking you
gautam

By js55

Date 03-22-2007 14:12

I believe part of the reason for a lack of responses is that the questions you ask are very comprehensive. The likely result of a single post addressing your questions as a whole is not going to say very much to help you. It also screams for clarifying questions such as; What sort of explanation of microstrucutre are you talking about? What is it you are trying to achieve with your etchant? What sort of comments are you looking for on hardnesses? And you really can't calculate the exact dimension of an HAZ because they are 'fractal' into the BM and fusion zone. You can estimate.
To sum up, I think your question(s) have two problems. You need to be more specific for each item, since the ambiguity could lead to a humungous discussion with no real answers for you, AND, it seems you are looking for one stop shopping in a single post when this really needs to be divided up for more specific discussions.
I sense an urgency in your need for answers and I think there are many people in here willing to help but perhaps you can attack your questions a little more specifically and patiently to get your answers.

By gautam agarwal Date 03-24-2007 20:02

hi,

i am not asking a single person to tell me about all those problems. whatever is known to you, you can tell. explanations:

1. plz explain something abt microstrucure of weld metal also (like explained in 2nd post by sir)
2. if u ve ne snap shot of microstructure wm, bm and haz then plz do send on my email
3. also tell me which etchant shud i use for micro and macro structure of these (A516 grade 70 weldment) bcos i have been using nital but structure what i am getting is very poor.
4. and plz comment on hardness of bm, wm and haz with quantitative values (like which is having higher hardness - wm or haz)
5. how can i calculate the exact length of the haz - is it using microstructure or hardness graph
6. i have done impact test at room temp for pm, wm and haz but i dont have std impact values of pm, wm and haz at room temp to compare whether my results are correct or not
7. what type of conclusion can be drawn from comparing tensile, impact, bend, hardness test and microstructure of A516 grade70 welded with E7018 using smaw and gmaw
7. can anyone tell the % monthly interest rate of equipment and ownership cost for equipments like smaw welding rectifire, gmaw rectifier unit with spool unit in his respective country
8. last but not the least what shud be the approx deposition rate, deposition efficiency and operating factor of smaw and gmaw welding.

hoping now it shud be clarified:
thanking you,
gautam
gautam.lntecc@gmail.com

By DaveBoyer (*****)

Date 03-25-2007 04:41

With regards to the last 2 questions, without going into actual numbers, I live in the USA. Here wages, benifits, insurances and other labor related costs are so high in relation to equiptment costs that for high production volume jobs the most productive methods are the most cost effective nearly every time regardless of equiptment costs. In a country with low labor costs this might not be the case. Deposition rates and operating factor varry too much from job to job to give a general answer. Deposition efficiency is generally high with GMAW, but with SMAW again varries greatly from job to job due to stub losses that can come from acess situations.