4140/4142, can be used for applications with a high degree of strength and toughness. 4140PH/4142PH (Pre-Hardened, PH) is often used in machine construction.
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Standard values
Working hardness:
27 HRC - 48 HRC
Delivery condition:
max. 217 HB
Chemical composition in %
0.380000
0.380.450000
0.450.000000
00.400000
0.40.600000
0.60.900000
0.90.000000
00.035000
0.0350.000000
00.035000
0.0350.900000
0.91.200000
1.20.150000
0.150.300000
0.3Technical properties
Heat-treatable steel (annealed condition) that can be used for a wide range of applications with a high degree of strength and toughness. Often used for demanding applications in automotive engineering. In quenched and tempered condition it is used in machine construction.
Applications
mechanical engineering, machine parts, axes, knuckles, connecting rods, crankshafts, gear shafts, pinions, gears, bandages, base plates, assembling parts
General Information
As a low alloy steel, 4140/4142, 4140PH/4142PH relies on the added chromium, molybdenum and manganese to increase strength and hardenability, yet it has inadequate weldability characteristics. The chromium content in this heat-treatable steel provides hardness penetration, whereas the added molybdenum provides uniform hardness and strength. The added manganese lends itself to increase strength and hardenability. This alloy may be used for both low and high temperature applications and with the relevant heat treatment can be used in sour gas environments as well.
In the quenched and tempered (PH) condition, it provides good wear resistance and has a minimum of 27 HRC which may be increased by flame or induction hardening or alternatively may as well be nitrided. In this condition, it is ready to use but still machinable as well.
Applications
Applications for this heat-treatable steel include: arbors, flanges, collets, bending dies, crankshafts, clutch parts, forming rolls and short run stamping dies.
Corrosion resistance
Molybdenum tends to increase corrosion resistance though the presence of iron can still cause some rust when exposed to different conditions. 4140/4142, 4140PH/4142PH though has excellent resistance to corrosion, which can be attributed to a significant percentage of chromium and molybdenum. That in mind, if corrosion has started, it will sustain the same damages as other non-corrosion resistant steels.
Heat treatment
Annealing
Uniformly heat the work piece to 1256-1328°F (680-720°C) followed with a slow cooling in the furnace.
Stress relieving
4140/4142 should be heated to 1100-1300°F (593-705°C), hold at that temperature for 2 hours and then cool the work piece in air.
4140/4142PH is heated slowly through to 900°F (482°C) and soak for 1 hour per inch (25.4 mm) thickness, then cool the material in the furnace or air to room temperature.
Normalizing
This steel grade can be normalized before hardening. Heat to 1544-1616°F (840-880°C), followed by air cooling.
Hardening
4140PH/4142PH is pre-hardened material, to reach a higher hardness the material has to be annealed, as described above, and then it can be re-hardened.
4140/4142 should be heated slowly and uniformly to 1508-1580°F (820-860°C) following with water or oil quenching, depending on the size and complexity of the work piece.
Quenching
4140/4142 can be quenched in oil to room temperature and should be tempered immediately.
Tempering
Alloy 4140/4142 can be tempered at 1004-1256°F (540-680°C) subject to hardness and according to the properties required. Cool in air after the treatment.
Alloy 4140PH/4142PH does not require a tempering as it is pre-hardened. If this material should be re-hardened, follow the annealing and hardening process as described above.
For our tempering diagram, please click here
Hot working
This steel can be hot worked at 1500-1900°F (816-1038°C), it maintains its properties even after long exposure at the high working temperatures.
Cold work
In its annealed condition, this steel can be cold worked with all the conventional methods.
Machinablility
This grade is easily machinable after it has been heat treated to produce the microstructure required for the best machinability.
Welding
Welding may only be done in the annealed or normalized condition, which can be done by all the conventional techniques. In order to prevent cracking, preheat to 350-650°F (177-350°C). Due to the level of carbon in this steel, pre- and post-heat is recommended. Cool slowly to prevent/reduce embrittlement.
If welded in the heat-treated condition, which is normally only done for repairs, mechanical properties are affected and a post-weld heat treatment should be performed. Welding pre-heated parts, it is recommended to stress relieve the parts before at a temperature 60°F (15°C) below the original tempering temperature in order to prevent cracking.
Disclaimer
The data shown here has been compiled with the greatest diligence and is regularly updated with regard to the correctness and completeness of its content. The content is indicative only and should not be taken as a warranty of specific properties of the product described or a warranty of suitability for a particular purpose. All information presented is given in good faith and no liability will be accepted for actions taken by third parties in reliance on this information. ABRAMS Industries reserves the right to change or amend the information given here in full or parts without prior notice.