hardfacing and welding cost approaches ?

Date 05-06-2010 22:40

i want to know what is meant by hardfacing in welding ?
as i read when you determine the cost of welding : there are three approaches one is called cost per unit,cost per length , and cost per weight ( which the article said it is used for hardfacing applications requiring significant quantities of metal to be replaced by welding ) so i want to know what is the difference between them and what is meant by hardfacing application ??
here is the site for welding cost approaches : http://weldingdesign.com/processes/news/wdf_10760/index.html
thanks in advance
mohamed fatehy

By waccobird (****)

Date 05-06-2010 22:54

fatehy88
Hardfacing is a welding technique to harden an area, rebuild old, worn-out components, and just about what it says.
They were using it as a prime example to figure welding costs per weight.
Hope this helps
Marshall

By fatehy88 (*)

Date 05-06-2010 23:17

thank you dear marshall for your help but actually i want to know is the hard facing is any operation required high deposited metal or not ?
so i am working on estimating cost for pipe welding (carbon steel pipes) with different thicknesses and different root gabs,..... etc and other parameters
and it will may require multi number of passes which cost approach i can use ??
thanks

By MMyers

Date 05-07-2010 12:44

No, hardfacing is a specific overlay technique used for a particular reason. It has nothing to do with volume of metal, it just so happens that usually if you're hardfacing, you are laying down lots of metal. I have seen very large overlays, and some the size of a quarter (valve seats need to be overlayed, and small valves don't need alot of metal). It all depends on what you're after.

By Metarinka (****)

Date 05-10-2010 16:55 Edited 05-10-2010 16:59

I saw your post on another forum. If you're doing large multiple pass weldments, deposition rate is probably the approach I would use.

Find the volume of your weld joint, multiplied by the number of joints to get your total weld volume. Then divide the volume by the deposition rate of the process you will use which will give you the total amount of arc time, and the total amount of material needed.

That would be the strategy I would use.

By fatehy88 (*)

Date 05-10-2010 23:16

Thank you Mr Metarinka for your reply but actually i want answers to the following if it possible
i want to know if it wright to calculate the cost ($/foot) for one pass and multiply it with total length of pass to determine the cost for the 1st pass and add the costs of the other passes for the same welding joint ?? is it wright or wrong .
and how can i calculate the length of pipe ( which contain outer and inner diameter ) can i use the average diameter as a circumference (length) for the pipe and multiply it with the area to determine the volume .
as your approach regarding calculating the cost per weight for multiple number of passes may be not accurate, because your deposition rate well change every pass as the ampire change and may be use one electrode for root pass and another for second passes, also the length (to calculate the volume ) will be changed because of the inner and outer diameter....
so actually i don't know what is wright ???!!!
please advice
thank you very much .