What did you use for the etch?Hi all,
I did a macro etch this week and was hoping if someone can explain why the weld metal is lighter than the parent metal of mild steel?
Ahh, seems hard stuff to get hold of! I was hoping you’d found an off the shelf product... I’ve only managed to find lab supply companies for the acid (2.5L min size!)You mean the acid? 10% nitric.
Get Yourself some rust dissolver with phosphoric acid (50% or up). Available off the shelf and works great for etching mild steel.Ahh, seems hard stuff to get hold of! I was hoping you’d found an off the shelf product... I’ve only managed to find lab supply companies for the acid (2.5L min size!)
Thanks a bunch! I’ll give it a go!Get Yourself some rust dissolver with phosphoric acid (50% or up). Available of the shelf and works great for etching mild steel.
I use the one from HG. I think that brand is available in the UK.
HG rust remover | thé effective rust remover
Just ordered, £8 on amazonThanks a bunch! I’ll give it a go!
It was an absolute nightmare!!!!Ahh, seems hard stuff to get hold of! I was hoping you’d found an off the shelf product... I’ve only managed to find lab supply companies for the acid (2.5L min size!)
This was brilliant.The chemical composition is different......the mild steel is basically Iron with a little bit of Carbon plus impurities.........the weld metal is the same plus perhaps 0,4%Silicon and 0.5% manganese.....these additions help produce similar mechanical properties in the "as cast" condition to the wrought mild steel..........these differences in composition alter the corrosion resistance and therefore the acid attacks one side more than the other.
So, let me try and get my head around this - the difference in colour / appearance post-acid is a combination of the different grain structure (due to the random allocation of grains v rolled grains) as well as the way difference in corrosion resistance (due to the differences in composition)?The chemical composition is different......the mild steel is basically Iron with a little bit of Carbon plus impurities.........the weld metal is the same plus perhaps 0,4%Silicon and 0.5% manganese.....these additions help produce similar mechanical properties in the "as cast" condition to the wrought mild steel..........these differences in composition alter the corrosion resistance and therefore the acid attacks one side more than the other.
thats itSo, let me try and get my head around this - the difference in colour / appearance post-acid is a combination of the different grain structure (due to the random allocation of grains v rolled grains) as well as the way difference in corrosion resistance (due to the differences in composition)?
deoxidisers yes, plus the Mn attaches itself to Sulphur making MnS which has little effect rather than FeS which embrittlesThis was brilliant.
Incidentally, the manganese and silicon are the / act as antioxidants also?