A Guide To 321H WIRE IN 2023
What is 321/321H Stainless Steel?
Stainless Steel 321 is a basic austenitic 18/8 steel (Grade 304) blend of chromium and nickel stabilized by Titanium (321) addition. SS 321 is used because they are not sensitive to intergranular corrosion after heating within the carbide precipitation range of 425–850°C. Stainless Steel 321 is the grade of choice for applications in the temperature range of up to about 900°C, combining high strength, resistance to scaling, embrittlement, and phase stability with resistance to subsequent aqueous corrosion. It is protected from temperatures ranging from 800 to 1500° F. The metal displays high strength and resistance to various forms of corrosion, including that from an aqueous environment.
321H Wire Supplier suggests these wires in applications like heavy welding components, along with dynamic environments that are subject to changes. Beyond this, stainless steel 321 has excellent forming characteristics, does not require annealing after being welded, and displays toughness in a range of temperatures. The metal shows strength even when exposed to cryogenic temperatures.
SS 321H Wire is a modification of SS 321 with a higher carbon content, to provide improved high-temperature strength. In addition, 321H is stabilized by the addition of niobium to resist intergranular corrosion. It is also able to withstand higher temperatures than type 321, due to its elevated carbon levels. While 321H displays the same welding and forming characteristics as type 321, the metal cannot be hardened by heat treatment. It is utilized in situations where type 321 cannot with high temperatures, typically those exceeding 1000° F. Type 321H displays better resistance against creep than both 321 and 304 stainless steel. 321H also shows resistance against acid corrosion in a variety of environments. Lower temperatures provide better resistance, but the metal is able to withstand up to a 10% acid solution, that has been diluted, at elevated temperatures. However, the metal shows very little resistance against chlorine or sulfuric solutions at any given temperature. Given their similar composition and characteristics, it is possible for stainless 321 and 321H to become dually certified.
Applications of Stainless Steel 321/321H Wire
For construction parts which should be resistant to scaling up to about 850°C and extensively inured to the effect of sulfurous gases. Inclination to carbonization in reduced gases is very low.
Expansion joints, Chemical and Petrochemical processing, Pharmaceutical production, Waste treatment including thermal oxidizers, Equipment, and storage units for Food processing, Aerospace Applications– piston engine manifolds, Food Processing — equipment and storage, Petroleum Refining — polythionic acid service, Exhaust Systems, Manifolds, Heat Exchangers, Piping, Furnace Parts, Chimney and Stack Liners, Storage Tanks, and Bellows
Equivalents of Stainless Steel 321/321H Wire
Standard: 321 321H — UNS: S32100 S32109 — WERKSTOFF NR: 1.4878 1.4541
Properties, Limitations, and Processing Characteristics of Stainless Steel 321/321H Wire
Properties
· Oxidation resistant to 1600°F and Stabilized against weld heat affected zone (HAZ) intergranular corrosion
· Resists polythionic acid stress corrosion cracking. Excellent resistance oxidation to 1500°F (816°C)
· Good low-temperature toughness and Comparable corrosion resistance and machinability to Type 304 and it is readily welded by most standard processes
· It is malleable and ductile and has good weldability and an austenitic structure allows it to be deep drawn without intermediate annealing. It is also unnecessary to anneal it following welding thin sections.
· It is generally recommended that Stainless 347 is used for welding rods and electrodes. (347 employs niobium and tantalum in preference to titanium)
· In its annealed state it is virtually non-magnetic even when cold worked, unlike 304 which can be significantly attracted to a magnet after cold working. This may make it more suitable for some applications.
· It also maintains its strength down to cryogenic temperatures. The key element that differentiates it from most other stainless steels is the inclusion of molybdenum, between 2% and 3%, which enhances its resistance to corrosion in general and pitting corrosion in particular.
Limitation
It is protected from temperatures ranging from 800 to 1500° F. The metal displays high strength and resistance to various forms of corrosion, including that from aqueous environments. Type 321 finds application in heavy welding components, along with dynamic environments that are subject to changes. The inclusion of molybdenum may have some adverse effects on its formability.
Processing / Welding
Alloy 321 stainless steel wire can be readily welded by most standard processes. Post-weld heat treatment is not necessary. Standard welding processes for this steel grade are TIG-Welding, MAG-Welding Solid Wire, Arc Welding (E), and Laser Bean Welding. In quenched conditions, the material can be slightly magnetizable. With increasing cold forming the magnetizability increases.
Fabrication Data and Other Properties of 321/321H Stainless Steels Wire
Alloy 321 stainless steel plate can be easily welded and processed by standard shop fabrication practices.
Cold Forming
• The alloy is quite ductile and forms easily.
Hot Forming
• The high sulfur content of Alloy 303 also has a detrimental impact on hot workability. If hot forming is required, once again, 304 should be considered as an alternate selection.
Machining
• The cold work hardening rate of 321 stainless steel plate makes it less machinable than 410 stainless steel, but similar to 304. The table below provides relevant machining data.
Heat Treatment and Resistance of Stainless Steel 321H Wire
321 resists oxidation up to 900°C in intermittent use and to 925°C in continuous use. It also avoids intergranular corrosion in the range of 425 and 850°C.
Annealing
• Annealing at 1800–2000 F (928–1093C) air cool. This process will result in maximum ductility. For maximum corrosion resistance, see the note on settled anneal under corrosion.
Hardening
- This alloy doesn’t harden by heat treatment. High properties may only be obtained through cold reduction.
Corrosion Resistance of Stainless Steel 321h Wire
• Exhibits good general corrosion resistance that is comparable to 304.
• Developed for use in the chromium carbide precipitation range of 1800–1500°F (427–816°C).
• Can be used in most diluted organic acids at moderate temperatures and in pure phosphoric acid at lower temperatures.
• Can be used in up to 10% diluted solutions at elevated temperatures.
• Resists polythionic acid stress corrosion cracking in hydrocarbon service.
• Utilized in chloride or fluoride-free caustic solutions at moderate temperatures and does not perform well in chloride solutions, even in small concentrations, or in sulfuric acid service.
Reference Link: https://www.steelpipesfactory.com/wp-content/uploads/2021/05/Datasheet-For-Stainless-Steel-321-321H.pdf — www.steelpipesfactory.com/– METALLICA METALS
