654SMO

HuaNickel 654SMO  steel series is based on the aforementioned 00Cr20Ni18Mo6CuN steel to increase chromium. A 7Mo type super austenitic stainless steel developed by nickel and molybdenum. The PRE value (Pitting Resistance Equivalent Value) of this steel is as high as 55. The nitrogen content in steel can reach about 0.5%, which is almost the highest amount of dissolved nitrogen at atmospheric pressure for stainless steel with high chromium (about 24%) and low manganese (about 3%). This steel has excellent resistance to various types of corrosion, and can replace iron-nickel-based or even nickel-based corrosion-resistant alloys in many media, thus filling the gap between stainless steel and high-nickel corrosion-resistant alloys without high pitting resistance and high crevice corrosion resistance stainless steel.

654SMO  Chemical composition：

	Mn	Cr	Ni	Mo	Cu	N	C	Si	P	S
Min	2	24	21	7	0.45	0.45	≤
Max	4	25	23	8	0.55	0.55	0.02	0.5	0.03	0.003

654SMO  Physical properties：

Density/g · cm-3	Specific heat capacity/J · (kg·K)-1	Resistivity /μΩ ·m	Young’s elasticity modulus/GPa	Thermal conductivity/W·(m·℃)-1
				20℃	100℃	200℃	300℃	400℃
8.00	510	0.78	188	8.6	9.8	11.3	12.6	14.5

654SMO Mechanical properties：

Mechanical properties
σb/MPa	σp0.2/MPa	δ/%	Impact power/J
			20℃	-196℃
≥750	≥410	≥40	250	125

654SMO Alloy properties：

HuaNickel 654SMO  steel has a single austenitic structure in its solid solution, which is the same as 6% Mo type super austenitic stainless steel. Because this steel belongs to 7% Mo section steel and the amount of chromium, molybdenum and nitrogen in the steel is very high, when the heat working, hot forming and heat treatment, welding and other processes are not suitable, it is more likely to have intermetallic phase and Cr₂N precipitation on the matrix, thereby damaging various properties of steel, especially plasticity, toughness and corrosion resistance.

654SMO Uses of alloys：

HuaNickel 654SMO  is mostly used in equipment, components, containers, heat exchangers and pipelines used in flue gas purification environments such as chemical industry, seawater, paper industry and flue gas desulfurization (FGD).

654SMO Process performance：

Welding process: The welding performance of this steel is good. It can be welded using the same welding method used in austenitic stainless steels. For manual arc welding, P16 electrodes are recommended.

Heat treatment: The suitable heat treatment process of 654SMO  steel is ≥ 1150°C heating and heat preservation and fast cooling.

Relevant standards：

ASTM A240/A240M-2020