Heat Treat Oven Ramps Slowly

[LABlade]

A machinist gave me a used Vcella (in Chula Vista, CA) heat treat oven. He used it to heat treat SS molds that are used in the medical field. It's a slow heating oven; takes about 3+ hours to ramp up to 1800-1900 F. Was wondering if that is a problem, i.e., too slow. For example, one of many specs I found for 440C SS was to soak it at 1400/1500 F for about 30 min., then ramp to 1850/1900 F and soak for 40 min. I can't find anything in any of the specs that addresses how fast the ramp temperature must be achieved for optimum results.

Further, this oven takes about 1 1/2 hrs. to ramp from 1500 F to 1850 F, then I would need to soak it at that temp for 40 min. (or whatever the particular spec is). Is the oven ramping up too slowly for this purpose?

If the oven is worth it I can upgrade the elements and switch to 240V, which will cut the ramp temps by 30 to 40% per the manufacturer. It is manually controlled and I can also upgrade it with a programmable controller, again if it's worth it. The total conversion would cost about $700.00. I might be better off just buying a new oven, huh?

Les

[Ed Caffrey]

Les,

In my experience, those times are about average...maybe just a tad on the slow side. My oven gets to 1400-1500F within about 1 1/2 hours, and is 3+ to get to 1950F. I thought something was wrong too, and replaced the element.....but no change in heat up time!

[LABlade]

Thanks, Ed. So it appears that I got a pretty good deal on this oven. I just heat treated a couple of 440C and ATS-34 kinves and they turned out good.

Les