Jiangsu Liangyi Co.,Limited |
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We are professional EN39B(AS X9315,15NiCrMo16-5,835M15,SNCM 815,,JIS G4103)Forged Forging DTH Hammer Drill Bits Body Bodies In Drilling Tool factory from china
EN39B is a 4 1/4% Nickel Chromium Molybdenum carburising steel, generally supplied annealed to HB 277 max. Carburised and heat treated it develops a hard wear resistant case of about Rc 6-63 and a tough strong core with a typical tensile strength range 1000-1400MPa, in small to quite large sections.
Forging
Heat to 1150°C and hold until uniform. Minimum forging temperature
900°C. Cool in ashes, warm dry lime or sand.Note: Soaking time at
forging temperature should be as short as possible to avoid heavy
scaling and excessive grain growth.
Heat Treatment
Annealing
Heat to 830oC - 850oC, hold until temperature is uniform throughout
the section and cool in furnace.
Normalising
Heat to 900°C - 930°C, Cool in still air
Temper at 640°C - 660°C Cool in still air
For optimum machinability
Stress Relieving
Heat to 600°C - 650°CCool in furnace to 450°C and air cool
Carburizing
Pack, salt or gas carburize at 900oC - 950oC, holding for
sufficient time to develop the required case depth and carbon
content, followed by a suitable hardening and tempering cycle to
optimise case and core properties.
Refining & Hardening
Core Refine
Slow cool from carburizing temperature and re-heat to 850oC -
880oC, hold until temperature is uniform throughout the section,
quench as required in water, oil or air cool. Alternatively quench
in salt bath held at 150oC - 250oC, followed by air cool.
Case Hardening
Following core refining, re-heat to 760oC - 800oC, hold until
temperature is uniform throughout the section, and quench in
oil.Temper immediately while still hand warm.
Single Refine*
Direct Quench: Cool from carburizing temperature to 810 oC - 830
oC, hold until temperature is uniform throughout the section.
Quench as required in water, oil or air cool. Alternatively quench
in salt bath held at 150 oC - 250 oC, followed by air cool and
temper immediately.
Or: Cool from carburizing temperature to room temperature, re-heat
to 810 oC - 830 oC and hold until temperature is uniform throughout
the section and quench or air cool as previous. Temper immediately.
Note: When air cooling large sections a uniform fan cooling is
recommended, especially when direct cooling from carburizing
temperature.
*Suitable for fine grained steels only.
Tempering
Heat to 150oC - 200oC as required, hold until temperature is
uniform throughout the section, soak for 1 - 2 hours per 25 mm of
section, and cool in still air.N.B.Tempering will improve the
toughness of both case and core, with only a slight reduction in
core strength and case hardness. It will also reduce the
susceptibility of the case to grinding cracks.
Welding
EN39B is readily weldable in the annealed condition with correct
procedure, but welding in the case hardened or through condition is
not recommended.
Welding Procedure
Low hydrogen electrodes recommended. Pre-heat at 250°C - 350°C and
maintain during welding. Cool slowly in ashes, warm dry lime or
sand etc, followed when possible with a stress relieve.
Name & Description | Forging Handling Capacities | Quantity |
3150 Tons Free Forging Hydraulic Press | Max. Single Forging in 28 Tons | 1 |
5000mm Diameter Rolling Forging Machine | Max. Single Forging in 16 Tons | 1 |
8 Tons Free Forging Hummer | Max. Single Forging in 7.5 Tons | 1 |
6 Tons Free Forging Hummer | Max. Single Forging in 5.5 Tons | 1 |
5 Tons Free Forging Hummer | Max. Single Forging in 4.5 Tons | 1 |
60 Tons Forging Handling Operator | Max. Single Forging in 45 Tons | 1 |
10 Tons Forging Handling Operator | Max. Single Forging in 7.5 Tons | 1 |
80 Tons Crane | Max. Single Ingot in 80 Tons | 1 |
60/30 Tons Crane | Max. Single Ingot in 60 Tons | 1 |
30/10 Tons Crane | 30/10 Tons | 4 |
Trolley Heat Furnace | 5000*1500*1200 mm | 3 |
Trolley Heat Furnace | 8000*2000*1600 mm | 3 |
Trolley Heat Furnace | 6500*1500*1200 mm | 3 |
Vertical Heat Furnace | Ø2500*10000 mm | 2 |
Total Forging Equipment Quantity | 24 |