Description
NX344 / 1.2344 ESR Forged Blocks for Plastic Mold
NX344 is a special grade which is developed by our Ningshing Special-Steel.
It is high quality level of 1.2344 ESR, a kind of hot work tool steel.
At the beginning, we develop this grade for making plastic mold for high-grade of snack box because of its better performance on thermal resistance and good toughness that could improve to get a longer lifetime of the mould.
Chemical Composition (%)
|
C |
Si |
Mn |
P |
S |
Cr |
Mo |
V |
|
0.36
0.42 |
0.90
1.20 |
0.30
0.50 |
≤
0.015 |
≤
0.003 |
5.00
5.50 |
1.25
1.50 |
0.90
1.20 |
Dimensions
|
Thickness (mm) |
Width (mm) |
Length (mm) |
|
100-500 |
100-910 |
3000-5800 |
Delivery Condition
EAF+LF+VD+(ESR), Forged, Spheroidizing Annealed, EFS, Hardness≤230HB, Machined surface,
UT 100% SEP1921 Class 3 E/e,
Spheroidized Microstructure as per standard NADCA207-2003 AS1-AS9
Impact test: Transverse impact test as per ASTM A370, V notch impact test (5 samples, size of 10 x 10 mm),
average value >=11 J (delete max. and min.), single value >=8 J
Forging Technique
|
Heat
Temperature |
Start Forging
Temperature |
Finish Forging
Temperature |
Cooling Method |
|
1020-1150 °C |
1100-1120 °C |
900-850 °C |
Pit or Sand Cooling |
Heat Treatment
Annealing
750 to 800°C (1382 to 1472°F)
Slow controlled cooling in furnace at a rate of 10 to 20°C/hr (50 to 68°F/hr) down to approx. 600°C (1112°F), further cooling in air.
Hardness after annealing: max. 235 HB.
Stress relieving
600 to 650°C (1112 to 1202°F)
Slow cooling in furnace; intended to relieve stresses set up by extensive machining, or in complex shapes.
After through heating, hold in neutral atmosphere for 1 - 2 hours.
Hardening
1000 to 1040°C (1832 to 1904°F)
Oil, salt bath (500 - 550°C / 932-1022°F), air
Holding time after temperature equalization: 15 to 30 minutes.
Obtainable hardness:
52 - 56 HRC in oil or salt bath,
50 - 54 HRC in air.
Tempering
Slow heating to tempering temperature immediately after hardening / time in furnace 1 hour for each 20 mm of work piece thickness, but at least 2 hours / cooling in air. It is recommended to temper at least twice. A third tempering cycle for the purpose of stress relieving may be advantageous.
1st tempering approx. 30°C (86°F) above maximum secondary hardness.
2nd tempering to desired working hardness.
The tempering chart shows average tempered hardness values.
3rd for stress relieving at a temperature 30 - 50°C (86 to 122°F) be low highest tempering temperature.
4. Contact us
Shanghai Bozhong Metal Group Co., Ltd.
ADD: 5F, Building #32, No.518 Xinzhuan Rd, Songjiang District, Shanghai, P.R.China 201612
Contact: Mr. Paik
Website: https://shanghaibozhong.en.made-in-china.com
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