UGI® 4512: Premium Ferritic Stainless Steel for High-Performance Applications

UGI® 4512 is a ferritic stainless steel stabilized with titanium and with a chromium content between 10.5 and 12.5%,

UGI® 4512 has some specific characteristics :

Cold heading properties close to the ones of low alloyed carbon steels

Good welding properties if welded in good conditions

Good oxydation resistance up to 800°C

Good corrosion resistance in outdoor atmosphere and mild agressive environnement.

The structure mainly ferritic gives to UGI® 4512 good ferromagnetic properties and a good oxidation re-sistance specially under cyclic thermal exposure like in exhaust lines.

Properties

General

Property	Value
Density	7.7 g/cm³

Mechanical

Property	Value
Elastic modulus	215 GPa
Elongation	45 %
Tensile strength	400.0 - 450.0 MPa

Thermal

Property	Temperature	Value	Comment
Coefficient of thermal expansion		0.0000105 1/K	20 to 100°C
		0.000012 1/K	20 to 200°C, 20 to 300°C
Specific heat capacity		460 J/(kg·K)
Thermal conductivity	23 °C	26 W/(m·K)
	500 °C	28.7 W/(m·K)

Electrical

Property	Value
Electrical resistivity	6e-07 Ω·m

Chemical properties

Property	Value	Comment
Carbon	0.03	max.
Chromium	10.5 - 12.5 %
Manganese	1.0	max.
Phosphorus	0.04	max.
Silicon	1.0	max.
Sulfur	0.15	max.
Titanium	0.65	min., max: 6x(C+N)

Technological properties

Property

Application areas

Exhaust line parts, Mufflers hooks

Cold Forming

Drawing or profil rolling: Like other ferritic steels, drawing UGI® 4512 is not difficult (see below the strain hardening curve of UGI® 4512 during drawing).

Cold heading: From a structural point of view, UGI® 4512 is fairly easy deformable via cold heading as most ferritic stainless steels. However, this grade is sensitive to lines of folded material on the outer surface of the wire rod formed during hot rolling. This type of defect may open during severe cold heading operations and torn up the outer surface ot the material when tensile stresses are high.

Forming and folding: Due to its structure, UGI® 4512 is well adapted to cold forming or folding work on both drawn wires and drawn bars.

Corrosion properties

UGI® 4512 provides a good corrosion resistance in mildly aggressive environnements.

UGI® 4512 has a high destructive scaling temperature thus exhibiting good scaling resistance in both contin-uous and intermittent service up to 800°C. Its weight loss when exposed for 100 h at 800°C is lower than 10 mg/cm², thus corrosion resistance of UGI® 4512 at such temperature is much better than alloyed car-bon steel.

UGI® 4512 shows good corrosion resistance specially towards acidic condensates found in both gasoline or diesel exhaust lines.

As many ferritic stainless steels, UGI® 4512 is not sensitive to stress corrosion cracking mechanisms.

Heat Treatment

A softening thermal treatment can be done in a temperature range from 800 to 850° followed by air cool-ing.This thermal treament transforms martensite formed during forging (or rolling) in parts where the structure is mainly ferritic containing precipitates of carbon, nitrogen and titanium. This ferritic structure ex-hibits a much better cold forming behavior than a structure containing both martensite and ferrite phases.

Hot forming

UGI® 4512 has a dual phase structure at high temperature (ferrite and austenite). It’s forging properties are then not as good as ferritic grades which exhibit 100% ferrite phase at high temperature. Forging proper-ties of UGI® 4512 remain however acceptable.

UGI® 4512 can be forged between 950 and 1200°C followed by a softening thermal treatment (see Thermal treatment paragraph) on forged parts to avoid generation of martensite phases during forging.

Other

Available products:

Product	Form	Finition	Tolerance	Dimension
Bars	Round	Drawn	h9	3 – 30 mm
	Round	Turned and polished	h10 – h11	22 – 71 mm
Wire rod	Round	Pickled		5 – 32 mm
Drawn wire	Round	Mat		3 – 16 mm

Other options: contact the supplier

Welding

UGI® 4512 has a good weldability. In order to avoid grain growth in the thermal affected zone, welding at high energies should be avoided.

UGI® 4512 is generally welded with argon as protective gas or a mix argon + helium. Addition of hydrogen or nitrogen in the mix of protective gases should be prohibited as it lowers ductility of welded areas.

Usage of CO₂ should not exceed 3% in the mix of protective gases for the same reasons.

Welded areas should be descaled mechanically or chemically and passivated afterwards.

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