38CrMoAl is an alloy structural steel characterized by high aluminum composition, which is generally used after quenching and nitriding.After nitriding, 38CrMoAl has high surface hardness, wear resistance and fatigue strength, and has [TJC STEEL]good heat resistance and corrosion.

The characteristic of 38CrMoAl nitriding is that the speed is fast and the depth of nitriding layer can be obtained. However, the brittleness of the nitriding layer is relatively large, so it is not suitable for making parts that bear great impact.

 

CHEMICAL COMPOSITION(%)

STANDARD	GB/T 3077	SAE 6470	JIS G4053	DIN EN 10085
GRADE	38CrMoAl	135 Mod UNS K24065	SACM645 （SACM1）	1.8509 41CrAlMo7-10
C	0.35~0.42	0.38~0.43	0.40~0.50	0.38~0.45
Si	0.20~0.45	0.20~0.40	0.15~0.50	≤0.40
Mn	0.30~0.60	0.50~0.80[TJC STEEL]	≤0.60	0.40~0.70
P	≤0.035	≤0.025	≤0.030	≤0.025
S	≤0.035	≤0.025	≤0.030	≤0.035
Cr	1.35~1.65	1.40~1.80	1.30~1.70	1.50~1.80
Mo	0.15~0.25	0.30~0.40	0.15~0.35	0.20~0.35
Al	0.70~1.10	0.95~1.30	0.70~1.20	0.80~1.20

 

HEAT TREATMENT

TYPES	TEM ℃	COOLING	HRC
ANNEALING	840~870	FURNACE COOLING	≤229HB
NORMALIZING	930~970	AIR COOLING	—
QUENCHING	940	OIL	＞56
TEMPERING	150~200	WATER OR OIL[TJC STEEL]	51~56
	300~400	WATER OR OIL	45~51
	500~550	WATER OR OIL	35~39
	600~650	WATER OR OIL	28~31

 

TRIDING TREATMENT

The process flow of nitriding parts is generally: forging → normalizing (annealing) → rough machining → tempering and tempering → finishing [TJC STEEL]machining → de-stress → fine grinding → nitriding → fine grinding → assembly.

The purpose of 38CrMoAl nitriding treatment is mainly for wear resistance.After nitriding, its hardness is as high as HV800, the hardened layer [TJC STEEL]can reach 0.30mm ~ 0.5mm.

 

APPLICATION

38CrMoAl is mainly used in the manufacture of parts with precise size, requiring high wear resistance and fatigue strength, and not subjected to large impact load, such as cylinder liner, bottom sleeve, gear, bolts, shaft and rotor, etc.

In addition, because Al and Cr elements can form a dense passivation film on the surface of steel, so 38CrMoAl is also a kind of seawater [TJC STEEL]corrosion resistant steel.Its seamless steel pipe is the most ideal pipeline and processing material for transporting water, oil and gas and seawater containing medium in coastal power plants, coastal oil fields, coastal natural gas and petrochemical plants.