AISI 4140 QT/SR TGP Alloy Round Bar Manufacturer – Anyang Longteng Heat Treatment Material Co.,Ltd

This medium carbon alloy grade is widely used for many general purpose parts requiring high tensile strength and toughness. 4140 contains chromium and molybdenum as alloying elements and may be heat treated over a wide range to give the combined hardness may be required, this steel is readily flame or induction hardened.

AISI 4140 Chrome- High Tensile Steel, generally supplied hardened and tempered to condition “T” in sections up to 100mm, with a tensile strength of 850-1000 MPa and aiming for this strength range in larger sections. It offers a very good balance of strength, toughness and wear-resistance.

Properties:

WEAR RESISTANCE           ——         Medium

TOUGHNESS                        ——         Very High

RESISTANCE TO SOFTENING EFFECT OF ELEVATED TEPERATURE ——  Low

DEPTH OF HARDENING  ——-     Medium

MACHINABILITY               ——-      Medium

GRINDABILITY                  ——-       High

DISTORTION IN HEAT TREATING ——  Medium

SAFETY IN HARDENING     ——-      low

RESISTANCE TO DECARBURIZATION  ——  Medium

TYPICAL APPLICATIONS:

Axles, conveyor parts, crow bars, gears, logging parts, spindles, shafts, sprockets, studs, pinions, pump shafts, rams, ring gears, etc.

Chemical Composition:

Carbon Silicon Manganese Chromium Molybdenum
0.40% 0.25% 0.85% 1.00% 0.25%

Relative Grades:

GB/T 3007, 42CrMo; DIN 1.723; EN 10883-1 42CrMo4; JIS G4105 SCM400

 

Typical Mechanical properties

Diameter Yield Strength Tensile Strength Elongation Impact Izod Hardness
mm MPa MPa % J HB
50 770 930 17 90 275
100 710 920 15 70 270
200 570 850 14 60 250

1) Forging

Preheat the steel carefully, then raise the temperature to 1150-1200°C for forging. Do not forge below 850°C.
2)Annealing

Heat the AISI 4140 slowly to 800-850°C and allow enough time for the steel to be thoroughly heated. Cool slowly in the furnace to 480°C followed by air cooling.
3)Stress Relieving

When parts are heavily machined, ground or otherwise subject to cold work, stress relieving will be beneficial prior to hardening.
4)Hardening

AISI 4140 steel is usually supplied ready heat treated to 18-22HRC. If further heat treatment is required annealed AISI 4140 should be heated slowly to 840-875°C and after adequate soaking at this temperature quench in oil. Temper as soon as the tools reach room temperature.
5)Tempering

Heat the AISI 4140 carefully to a suitable temperature selected by reference to a tempering chart or table (usually between 550-700°C, soak at the temperature for 2 hours per 25mm of ruling section, then allow to cool in air. Tempering between 250-375°C is not advised as tempering within this range will seriously reduce the impact value.

 

 

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Post time: Dec-20-2018