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BRB4140-60
BLACK ROUND-4140-60.00dia
4140 is a 1% chromium – molybdenum medium hardenability general purpose high tensile steel – generally supplied hardened and tempered in the tensile range of 850 – 1000 Mpa (condition T)
4140 is now available with improved machinability, which greatly increases feeds and/or speeds, while also extending tool life without adversely affecting mechanical properties.
Pre hardened and tempered 4140 can be further surface hardened by flame or induction hardening and by nitriding.
4140 is used extensively in most industry sectors for a wide range of applications such as: Adapters, Arbors, Axle Shafts, Bolts, Crankshafts, Connection Rods, Chuck Bodies, Collets, Conveyor Pins & Rolls, Ejector Pins, Forks, Gears, Guide Rods, Hydraulic Shafts & Parts, Lathe Spindles, Logging parts, Milling Spindles, Motor Shafts, Nuts, Pinch Bars, Pins Various, Pinions, Pump Shafts, Rams, Sockets, Spindles, Sprockets, Studs, Tool Holders, Torsion, Bars, Worms, etc.
COLOUR CODE: Dark Blue – bar end
FORGING: - Heat to 11150 – 1200degc maximum, hold until temperature is uniform throughout the section. Do not forge below 850degc. Following forging operation the work piece should be cooled as slowly as possible.
HEAT TREATMENT:
ANNEALING: - Heat to 800 – 850degc, hold until temperature is uniform throughout the section and cool in furnace.
FLAME OR INDUCTION HARDENING: - 4140 hardened and tempered bar can be further surface hardened by either the flame or induction hardening methods resulting in a case hardness in excess of Rc 50. Parts should be heated as quickly as possible to the austenitic temperature range of (840- 870degc) and “required case depth followed by an immediate oil or water quench, depending upon hardness required, workpiece” size/shape and quenching arrangements. “Following quenching to hand warm, most components should be tempered between 150 – 200degc to remove” quenching stresses in the case. This will have little effect on case hardness and will reduce the risk of grinding cracks.
HARDENING: - Heat to 840 – 875degc, hold until temperature is uniform throughout the section, soak for 10 – 15 mins per 25mm of section, and quench in oil, water or polymer as required. Temper immediately while still warm.
NITRIDING: - 4140 hardened and tempered bar can also be successfully nitride, giving a surface hardness of up to Rc 60. Nitriding is carried out at 490 – 530degc, followed by slow cooling (no quench) reducing the problem of distortion. Parts can therefore be machined to near final size, leaving a grinding allowance only. The tensile strength of the core is usually not affected since the nitriding temperature range is generally below the original tempering temperature employed.
NORMALIZING: - Heat to 870 – 900degc, hold until temperature is uniform throughout the section, soak for 10-15mins and cool in still air.
STRESS RELIEVING: - Heat to 680- 700degc, hold until temperature is uniform throughout the section, soak for 1 hour per 25mm section, and cool in still air.
TEMPERING: - Re-heat to 550 – 700degc as required, hold until temperature is uniform throughout the section, soak for 1 hour per 25mm of section, and cool in still air.
NOTES ON HEAT TREATMENT: Heating temperatures, rate of heating and soaking times will vary due to factors such as work piece size/shape also furnace type employed, quenching medium and work piece transfer facilities etc.
MACHINING: - 4140 in the hardened and tempered as supplied condition has good to very good machinability and operations such as sawing, turning, drilling, broaching, hobbing, milling and tapping can be carried out satisfactorily using machine manufacturers recommendations for suitable tool types – feeds and speeds.
WELDING: - Welding of 4140 in the hardened and tempered condition (as normally supplied), is not recommended and should be avoided if at all possible, as the mechanical properties will be altered within the weld heat affected zone. It is preferred that welding be carried out on 4140 while in the annealed condition, and that the work piece, immediately on cooling to hand warm, is then stress relieved at 595 – 620degc prior to hardening and tempering. If welding in the hardened and tempered condition is really necessary, then the work piece, immediately on cooling to hand warm, should be possible stress relieved at 15degc below the original tempering temperature (if know).
WELDING PROCEDURE: - Welding of 4140 in whatever condition should always be carried out using low hydrogen electrodes – please consult your welding consumables supplier.
POST WELDING: - Maximum cooling rate 95deg/hour down to 95deg, follow by cooling in still air. NB. No draught. It is recommended that the work piece if possible is wrapped in an heat resistant blanket or buried in sand etc.
Weight: 22.194 KG/MTR
MTR
LGTH

Category: MERCHANTS & BRIGHTS