The chemical composition of 347H stainless steel typically includes 17-19% chromium, 9-13% nickel, 3-4% manganese, 2% silicon, 0.08% carbon, and small amounts of other elements such as nitrogen, phosphorus, and sulfur. The high chromium and nickel content give 347H stainless steel excellent corrosion resistance, while the carbon content provides improved high temperature strength and creep resistance.

In terms of mechanical properties, 347H stainless steel has a tensile strength of 515MPa, a yield strength of 205MPa, and an elongation of 40%. It also has good toughness and ductility at both low and high temperatures. Additionally, 347H stainless steel has a high resistance to intergranular corrosion and stress corrosion cracking.

Some key features of 347H stainless steel include its excellent resistance to oxidation, its high temperature strength and creep resistance, and its good weldability and formability. It is also resistant to many chemicals commonly used in industrial processes, such as sulfuric acid and hydrochloric acid.

Due to its unique combination of chemical and mechanical properties, 347H stainless steel is commonly used in a variety of industries, including chemical processing, petrochemical, oil and gas, and power generation. It is often chosen for applications where high temperature strength and oxidation resistance are required, as well as for applications involving corrosive environments. Some specific applications of 347H stainless steel include heat exchangers, furnace parts, boiler tubes, and chemical processing equipment.