Failed Heattreat

[joe sangster]

I heat-treated some filet knives of 1/16" stock ow what was supposed to be ATS- 34. I ,used the recipe that I usually use for my other knives of ATS -34 , preheating the kiln to 1500 degrees F. before placing the prewrapped steel with steel foil ,then ramped up to 1975 degrees & held for 30 min before air cooling with aluminium plates . They were softer before heat-treat than after. The only way I can explain it is that I used mistakenly identified steel. Can anyone offer other suggestions ?

Thanks,
Joe

[mete]

If you've done ATS-34 successfully before and you're following the same procedures I think mis- identified steel is the probable cause.

[joe sangster]

Thanks , Mete . I think that must have been the problem. I have heat treated ATS-34 for a couple yrs with same kiln & same recipe with consistent results up until the 1/16 " filet knives . Someone stipped some bad stuff in on my last order of steel !

joe