XAL4 | Paralloy Group | Paralloy Group

23/43 Cr/Ni 3.5% Al 0.4% C

Alumina Forming Alloy
Steam Cracking

Application

Alumina Forming Alloy Developed To Face Coke Formation And Carburization Issues

XAl4 is a nickel-based alloy developed to face coke formation and carburization issues encountered within steam-crackers for ethylene production. Its oxidation and mechanical properties are a result of its specific chemical composition. With its 4% aluminum content, XAl4
develops a uniform, auto-protective and self-healing oxide layer with very high thermal stability suitable for steam crackers service conditions.

Aluminum oxide being much more stable than chromium oxide, alumina forming alloys exhibit much better oxidation and carburization resistance than their chromia forming equivalent. The enhancement of high temperature oxidation resistance contributes to improve carburization and coking resistance.The mechanical properties of this micro-alloyed grade, including creep resistance, have been carefully optimised through balance of chemical composition and overpass the level of standard 35/45 XTM heat-resistant alloy.

Nominal Composition

6
C Carbon

0.4
13
Al Aluminium

3.5
28
Ni Nickel

43
24
Cr Chromium

23
Plus
Additions

Physical Properties

Temperature	Thermal Conductivity (W/m°C)	Thermal Expansion Coefficient (10⁻⁶/K)	Density	Elasticity Modulus (GPa)
20°C	10.5		7.5 g/cm3	168
800°C	24	17.6		121
900°C	25.3	18.1		112
1000°C	26.7	18.6		101
1100°C	28.1	18.8		94

Mechanical Properties

Download specifications

UTS (N/mm²) 500
Proof Stress 0.2% (N/mm²) 300
Elongation (%) 6
Temp (°C) 10,000 Hour Life 100,000 Hour Life
Minimum Mean Minimum Mean
900 27.5 35.0 20.8 26.2
950 20.2 25.4 14.4 18.1
1000 14.1 17.7 9.5 11.9
1050 9.4 11.8 5.9 7.5
1100 6.0 7.6 3.5 4.5
1150 3.6 4.7 2.0 2.6
1200 2.1 2.7 1.0 1.4