XMR | Paralloy Group

25/35 Cr/Ni Si 0.4% C

Creep Resistant
Steam Reforming

Application

25/35 - Enhanced Creep Properties

XMR is an alloy that was developed over a number of years, demonstrating incremental improvements at each stage of development. XMR material was especially developed for Reformer furnace applications and the creep properties lie between those of H39WM and H39WM+.

The high creep rupture strength makes XMR ideal for steam reformer furnaces where high tube temperatures or thinner tube walls are required. The creep strength of microalloyed XMR, is based upon a proven track record of success within the petrochemical industry over many years.

XMR is a weldable chromium nickel heat resisting steel which is a low Silicon version of H39WM (HP Nb microalloy). The optimised lower Silicon content adds creep strength to the alloy by re-organising the chemical elements at the interdendritic space zone near the primary carbides.

Nominal Composition

6
C Carbon

0.4
14
Si Silicon

0.8
25
Mn Maganese

1
24
Cr Chromium

25
28
Ni Nickel

35
43
Nb Niobium

1
Plus
Additions

Phyiscal Properties

Coefficient Of The Thermal Expansion (mm/mm°C)	Thermal Conductivity (W/m°K)	Density (kg/m³)	Young Modulus (N/mm2 x 10³)	Elasticity Modulus (GPa)
20 - 100°C - 15.5 x 10-⁶	100°C - 13.0	7.97 x 10³	20°C - 158.5	455
20 - 800°C - 18.9 x 10-⁶	750°C - 24.3		800°C - 108.2
20 - 1000°C - 19.4 x 10-⁶	1000°C - 27.7		1000°C - 95.1
20 - 1100°C - 19.7 x 10-⁶	1000°C - 29.7

Mechanical Properties

Download specifications

UTS (N/mm²) 450
Proof Stress 0.2% (N/mm²) 250
Elongation (%) 8 (tubes) 6 (statics)
Temperature UTS (N/mm²) Proof Stress 0.2% (N/mm²) Elongation (%)
800°C 265 136 31
900°C 172 94 38
1000°C 117 66 43
1100°C 82 50 45

Temp (°C)	10,000 Hour Life		50,000 Hour Life		100,000 Hour Life
	Minimum	Mean	Minimum	Mean	Minimum	Mean
800	66.53	73.92	58.8	65.33	55.48	61.64
850	52.59	58.43	44.84	49.83	41.65	46.27
900	39.5	43.88	32.41	36.01	29.59	32.88
925	33.58	37.3	27	30	24.43	27.14
950	28.18	31.31	22.19	24.65	19.89	22.1
975	23.35	25.94	17.99	19.99	15.98	17.75
1000	19.1	21.22	14.4	15.99	12.66	14.07
1025	15.43	17.14	11.36	12.63	9.89	10.99
1050	12.3	13.67	8.85	9.83	7.62	8.47

Download specifications

UTS (N/mm²)	450
Proof Stress 0.2% (N/mm²)	250
Elongation (%)	8 (tubes) 6 (statics)

Temperature	UTS (N/mm²)	Proof Stress 0.2% (N/mm²)	Elongation (%)
800°C	265	136	31
900°C	172	94	38
1000°C	117	66	43
1100°C	82	50	45

Temp (°C)	10,000 Hour Life		50,000 Hour Life		100,000 Hour Life
	Minimum	Mean	Minimum	Mean	Minimum	Mean
800	66.53	73.92	58.8	65.33	55.48	61.64
850	52.59	58.43	44.84	49.83	41.65	46.27
900	39.5	43.88	32.41	36.01	29.59	32.88
925	33.58	37.3	27	30	24.43	27.14
950	28.18	31.31	22.19	24.65	19.89	22.1
975	23.35	25.94	17.99	19.99	15.98	17.75
1000	19.1	21.22	14.4	15.99	12.66	14.07
1025	15.43	17.14	11.36	12.63	9.89	10.99
1050	12.3	13.67	8.85	9.83	7.62	8.47