Lines in finish

[Stacy E. Apelt - Bladesmith]

Stacy, are you sure about the full normalization process recepit for 440c?

Thanks Stezann, I thought it was O-1. I'll edit the post.

 

[Matt Rochester]

Thanks Stezann, I thought it was O-1. I'll edit the post.

Dang. Can I normalize 440c?

 

[stezann]

You can, but it wouldn't be a good idea.
Normalizing (at higher temperatures than for carbon steels) would put into solution all the carbon, and air cooling would redistribute the carbides in a fine state.
Problem is that ledeburitic steels have so much alloy elements that for dissolving you would approach melting temperatures. That is why huge carbides forms already in the melt and won't move at lower temps.
Powder steels have been developed to allow a fine setup of those high volume carbides, but normally even a traditional process and good mill's job keeps them at bay good enough to work with.
If big lumps of carbides are the result of an error at the mill or during ht you let the carbides coalesce into big lumps there is little to do to erase the situation but change the steel batch. Generally big carbides tend to get bigger at the expense of smaller ones, and are the least to dissolve.

 

[mknife]

Steels not made with dust technology can occur. I had knives in 440C, 154CM and ATS34 in which was visible a "plot" similar. If you satins the knife you will continue to see, anyway, a good mirror polishing partially eliminate this effect. In the practical use of the knife, I never had connected problems

As has already been written if you want steels more controlled, similar in composition to 154CM, you must use CPM154, RWL34.

_________________________________________________
Riccardo Mainolfi
p.s. sorry for my poor english.

 

[Matt Rochester]

Could this be a result of my heat treat? 1400 for 15 mins, 1900 for 30 mins. Plate quench with compressed air. Temper for 1 hour at 400.

You can, but it wouldn't be a good idea.
Normalizing (at higher temperatures than for carbon steels) would put into solution all the carbon, and air cooling would redistribute the carbides in a fine state.
Problem is that ledeburitic steels have so much alloy elements that for dissolving you would approach melting temperatures. That is why huge carbides forms already in the melt and won't move at lower temps.
Powder steels have been developed to allow a fine setup of those high volume carbides, but normally even a traditional process and good mill's job keeps them at bay good enough to work with.
If big lumps of carbides are the result of an error at the mill or during ht you let the carbides coalesce into big lumps there is little to do to erase the situation but change the steel batch. Generally big carbides tend to get bigger at the expense of smaller ones, and are the least to dissolve.

 

[Matthew Gregory]

Probably, not, Matt. This is an artifact from before you got it, I suspect. Like James said, the 'conventional' steels seem to be getting sketchier and sketchier of late. I had some O1 flat ground stock that was insanely orange peeled... All points to doing your research, and buying from vendors that do the diligence, and maybe finding a good lot and stocking up on it, I guess.

OR, like James said, shifting gears and going to something else with a better track record.