Stainless steel pipe continuous solution annealing by induction heating

[Saad M.M.]

Hello,

Anyone familiar with stainless steel pipe continuous solution annealing by induction heating. I am reviewing a 316L SS pipe specification. The induction heating zone length is about 600 mm and the pipe forward speed is about 400 mm/min. The temperature was monitored by two pyrometers that are 400 mm apart and both measuring 1060 C. The heater zone is followed by water ring quenching. Water cooling was effective and pipe can be touched by hand after cooling.

For a 6” x 0.38” stainless steel 316L pipe, the solution annealing lasted about one (1) minute at 1060 C through the induction heating zone. Is this enough?
What if the pipe was cold drawn seamless pipe? What if the pipe was welded pipe with filler metal?

 

[jessieleo99]

For the wall thickness of 0.38”, induction heating at 1060°C for 1 minute should be sufficient assuming uniform heat penetration.

 

[EdStainless]

You can test to see.
Measure how magnetic hte welds are before and after anneal.
My guess is that you will still have some residual ferrite but a lot less than as welded.
This should work fine.
the trick is that the pipe will heat through quickly be induction.