Generally, austenitic stainless steel doesn’t have magnetism. But the martensite and ferrite have magnetism. However, the austenitic may also be magnetic. The reasons are as follows:

When solidified, part magnetism may leave due to some smelting reason; take 3-4 for example, 3 to 8% residual is a normal phenomenon, so the austenite should belong to non-magnetism or weak magnetism.

Austenitic stainless steel is non-magnetic, but when part γ phase generates into martensite phase, magnetism will generate after cold hardening. Heat treatment can be used to eliminate this martensite structure and restore its non-magnetism.