XTM | Paralloy Group | Paralloy Group

35/45 Cr/Ni 0.4%C

Chromia Forming Alloy
Steam Cracker

Application

XTM An Excellent Choice For Heavy-Duty Pyrolysis Cracker Coils.

XTM was developed for use in elevated temperature applications where high creep strength and corrosion resistance is required. XTM is an excellent choice for heavy-duty Pyrolysis Cracker Coils where coke formation and carburisation are most severe and end of run temperatures can reach 1125°C or above.

The high nickel content of XTM ensures superb resistance to carburisation and the very high chromium content aids the formation of a more protective oxide film on the internal bore surface of the coils. This oxide film acts as further protection against carburisation. Niobium increases the creep rupture strength and the controlled “Microalloy” addition of specially selected elements not only ensures further strength improvements, but also contributes to improved carburisation resistance

Nominal Composition

6
C Carbon

0.4
14
Si Silicon

1.6
25
Mn Maganese

1
24
Cr Chromium

35
28
Ni Nickel

45
43
Nb Niobium

1
Plus
Additions

Physical Properties

Coefficient of Thermal Expansion (mm/mm°C)	Thermal Conductivity (W/m°K)	Density (kg/m³)	Young Modulus (N/mm² x 103)	Specific Heat (J/KgK)
20 – 100°C – 15.6 x 10⁻⁶	100°C – 13.8	7.97 x 10³	20°C – 176.5	480
20 – 800°C – 18.8 x 10⁻⁶	800°C – 25.9		800°C – 127.2
20 – 1000°C – 19.2 x 10⁻⁶	1000°C – 28.3		1000°C – 109.1
20 – 1100°C – 19.5 x 10⁻⁶	1100°C – 31.5

Mechanical Properties

Download specifications

UTS (N/mm²) 450
Proof Stress 0.2% (N/mm²) 250
Elongation (%) 4

Temp (°C)	10,000 Hour Life		50,000 Hour Life		100,000 Hour Life
	Minimum	Mean	Minimum	Mean	Minimum	Mean
950	22.08	26.07	17.59	20.76	15.83	18.68
975	18.63	21.99	14.49	17.1	12.9	15.23
1000	15.5	18.29	11.76	13.88	10.36	12.23
1025	12.71	15.01	9.41	11.11	8.19	9.67
1050	10.28	12.14	7.41	8.75	6.38	7.54
1075	8.2	9.68	5.76	6.8	4.9	5.78
1100	6.45	7.62	4.41	5.2	3.7	4.37
1125	5.01	5.91	3.32	3.92	2.76	3.26
1150	3.83	4.52	2.47	2.91	2.02	2.39

Download specifications

UTS (N/mm²)	450
Proof Stress 0.2% (N/mm²)	250
Elongation (%)	4

Temperature (°C)	UTS (N/mm²)	0.2% (N/mm²)	Elongation (%)
820°C	226	106	30
950°C	175	67	36
1050	113	41	44
1150	59	28	47

Temp (°C)	10,000 Hour Life		50,000 Hour Life		100,000 Hour Life
	Minimum	Mean	Minimum	Mean	Minimum	Mean
950	22.08	26.07	17.59	20.76	15.83	18.68
975	18.63	21.99	14.49	17.1	12.9	15.23
1000	15.5	18.29	11.76	13.88	10.36	12.23
1025	12.71	15.01	9.41	11.11	8.19	9.67
1050	10.28	12.14	7.41	8.75	6.38	7.54
1075	8.2	9.68	5.76	6.8	4.9	5.78
1100	6.45	7.62	4.41	5.2	3.7	4.37
1125	5.01	5.91	3.32	3.92	2.76	3.26
1150	3.83	4.52	2.47	2.91	2.02	2.39