347 stainless steel pipe

347 is a stabilized austenitic chromium steel containing niobium which eliminates carbide precipitation and therefore intergranular corrosion. Alloy 347 is stabilized by the addition of chromium and tantalum and provides higher creep and stress rupture properties than Alloys 304 and 304L, which may also be used in exposures where sensitization and intergranular corrosion are a concern. The addition of columbium also gives Alloy 347 excellent corrosion resistance, even better than Alloy 321. 347H is the higher carbon content form of Alloy 347 and exhibits improved high temperature and creep properties.

Type 347 is a stabilized austenitic stainless steel similar to Type 304, but with the addition of columbium and tantalum. Columbium is used to produce stable stainless steels that are not affected by chromium carbide precipitation. Therefore, this type of grade is recommended for parts that are manufactured by welding and cannot be subsequently annealed or that must operate between 800 - 1600 °F.

chemical composition

Chemical Composition (wt%) limits as specified in ASTM A240 and ASME SA240*.

Element	347
Carbon	0.08
Chromium	17.0-19.0
Nickel	9.0-13.0
Manganese	2.00
Silicon	0.75
Phosphorus	0.045
Sulfur	0.030
Niobium	10 x C min / 1.00 max

Carbon: 0.08 max
Manganese: 2.00 max
Silicon: 0,75 max
Chromium: 17.00-19.00
Nickel: 9.00-12.00
Molybdenum: 0.75 max
Columbium + Tantalum: 10 x (Carbon+ Nitrogen) min-1.00 max
Phosphorus: 0.040 max
Sulfur: 0.030 max
Copper: 0.75 max Iron: Balance

Features

Manufacturing and heat treatment
Machinability
Machined grade 347H stainless steel is slightly tougher than grade 304 steel. However, the hardenability of this steel can be minimized by using constant forward feed and low speeds.

welding
Grade 347H stainless steel can be welded using most resistance and fusion methods. Oxyacetylene welding is not preferred for this type of steel.

Thermal processing
Forging, upsetting and other hot working processes can be performed at temperatures from 1149 to 1232°C (2100 to 2250°F). Grade 347H steel must be water-quenched and annealed to achieve maximum hardness.

Cold working
Grade 347H stainless steel is very tough and ductile, making it easy to stamp, blank, spin and draw.

annealing
Grade 347H stainless steel can be annealed in a temperature range of 1010 to 1193°C (1850 to 2000°F) and then quenched with water.

hardening
Grade 347H stainless steel does not respond to heat treatment. The hardness and strength of steel can be increased by cold working.

Applications

Alloy 347 is frequently used in the manufacture of equipment that must be used in severe corrosive conditions and is also common in the petroleum refining industry. Applications where Alloy 347 has been consistently used include:

high temperature chemical process
Heat exchange tube
High temperature steam service
High pressure steam pipe
Radiant superheater
boiler tube
Heavy duty exhaust system
General Refinery Pipeline

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FAQ

Q: How many coutries you already exported ?
A: Exported to more than 50 countries mainly from America, Russia, UK, Kuwait, Egypt, Turkey, Jordan,India, etc.

Q:What product information do I need to provide?
A:You need to provide the grade, width, thickness, coating and the number of tons you need to purchase.

Q:What are the shipping ports?
A:Under normal circumstances, we ship from Shanghai, Tianjin, Qingdao, Ningbo ports, you can choose other ports according to your needs.

Q:About 347 seamless stainless steel product prices?
A:Prices vary from period to period due to cyclical changes in the price of raw materials.

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