The department said it is launching the inquiry based on its own monitoring of trade patterns. Stainless sheet and strip shipments from Vietnam have increased in value by US$122 million, or 180.4%, in the 40 months following the imposition of anti-dumping and anti-subsidy duties on Chinese stainless sheet and strip, the department said. 

Commerce officials also said they will concurrently explore whether stainless sheet and strip from Vietnam should be subject to the original duties. Those duties are to be applied to stainless sheet and strip that has undergone certain types of minor processing in third countries.