I am going to have a spherical pressure vessel made. I need to know which grade of stainless steel suits best. The pressure vessel will contain liquefied diluoromethane at 1.8Mpa with tetrabutylammonium hexafluoroborate. The pressure vessel will also be cooled to temperatures as low as -60 degrees Celsius and must have very poor electrical conductivity qualities to be able to make sure the stainless steel doesn't interfere with the experiment. With this knowledge can you recommend the best stainless steel for the job. Thanks.
P.S. The pressure vessel will be very small so please take this into account.