AISI 4140 L80 Alloy Steel Bar

• Type: Alloy Steel Bar
• Standard: AISI
• Technique: Forged
• Shape: Bar
• Transport Package: Strip
• Trademark: SHUNFU
• Model NO.: 4140 L80
• Origin: China
• Production Capacity: 50000tons/Year

Product Description

AISI 4140 L80 Alloy Steel

 

Introduce

AISI 4140 80K, PSL 3, API 5CT Standards, NACE MR0175:2015
 

Chemical Composition

Grade	C	Mn	Cr	Mo	Si	P	S	Ni	Cu	V	H max. ppm
Min.	0.380	0.750	0.800	0.150	0.150	-	-	-	-	-	-
Max.	0.430	1.000	1.100	0.250	0.350	0.025	0.025	0.250	0.300	0.300	2.000

 

Heat Treatment

Austenizing temperature	Time	Tempering temperature	Time
1600 ±25ºF (871 ±14ºC)	Min. 60 minutes	1250 ±50ºF (677 ±27ºC)	Min. 60 minutes

Oil or Polymer or Water. For Water Quenching, the temperature of water shall not exceed 38ºC (100ºF) at start of quench. For bath-type quenching, the temperature of water shall not exceed 49ºC(120ºF) at any time during the quench cycle.

Mechanical Properties

as per ASTM A370 -20

Yield strength	Tensile strength minimum	Elongation in 2" (minimum)	Reduction Area  (minimum)
Min. 80,000 psi (552 MPa) Max. 95,000 psi (655 MPa)	100,000 psi (690 MPa)	18%	35%

 

Heat Treatment  

AISI 4140 alloy steel is heated at 845°C (1550°F) followed by quenching in oil. Before hardening, it can be normalized by heating it at 913°C (1675°F) for a long period of time, followed by air cooling.
 

Forging  

AISI 4140 alloy steel is forged at 926 to 1205°C (1700 to 2200°F)
 

Hot Working 

AISI 4140 alloy steel can be hot worked at 816 to 1038°C (1500 to 1900°F)
 

Cold Working  

AISI 4140 alloy steel can be cold worked using conventional methods in the annealed condition.
 

Annealing 

AISI 4140 alloy steel is annealed at 872°C (1600°F) followed by slowly cooling in the furnace.
 

Tempering  

AISI 4140 alloy steel can be tempered at 205 to 649°C (400 to 1200°F) depending upon the desired hardness level. The hardness of the steel can be increased if it has a lower tempering temperature. For example, a tensile strength of 225 ksi can be achieved by tempering at 316°C (600°F), and tensile strength of 130 ksi can be achieved by tempering at 538°C (1000°F).
 

Hardening  

AISI 4140 alloy steel can be hardened by cold working, or heating and quenching.
 

Machinability  

AISI 4140 alloy steel has good machinability in the annealed condition.
 

Forming  

AISI 4140 alloy steel has high ductility. It can be formed using conventional techniques in the annealed condition. It requires more pressure or force for forming because it is tougher than plain carbon steels.
 

Welding  

AISI 4140 alloy steel can be welded using all conventional techniques. However, the mechanical properties of this steel will be affected if it is welded in the heat-treated condition, and post-weld heat treatment should be performed.

Quality Inspection

1. Specimen test location & QTC
2. Charpy V-notch impact at 21ºC / -32ºC / -60ºC
3. Hardness as per ASTM E10-18: On surface / 1" below surface
4. Volumetric NDE 100% - Ultrasonic
5. Minimum hot work reduction ratio 4.0 to 1
6. Grain size should be #S or Finer as per ASTM E112 - 13
7. Surface inspection