347H stainless steel name: Austenitic Stainless steel: AISI, ASTM Type: 347H UNS Number: S34709 ● 347H features and applications: 347H austenitic stainless steel heat resistant steel with good corrosion resistance, weldability and heat strong performance. 347H stainless steel used in large boiler superheater reheater ﹑ ﹑ steam pipes, petrochemical heat exchanger tube. ● 347H chemical composition ①: C C: 0.04 ~ 0.10 Manganese Mn: ≤ 2.00 Si Si: ≤ 0.75 Chromium Cr: 17.0 ~ 19.0 Ni-Ni ②: 9.0 ~ 13.0 P P: ≤ 0.045 S S: ≤ 0.03 Niobium Nb: (8C ~ 1.00)