Slloy Steel with SKD61 Cold Work Drawn Toll Stainless Steel Plate Metal Sheet Pipe Bar

• Type: Sheet
• Standard: AISI, ASTM, DIN, JIS, GB, BS
• Composition: Check Detailed Description
• Model NO.: SKD61
• Technique: Forged
• Shape: Plate
• Surface Treatment: Black, Machined
• Special Use: High-strength Steel Plate, Wear Resistant Steel, Silicon Steel, Cold Heading Steel, Free Cutting Steel, Mold Steel
• Application: Tool Steel Bar
• Transport Package: Nude Packing
• Specification: check detailed description
• Trademark: Ningbo Ningshing
• Origin: China

Product 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	0.90	0.30	≤	≤	5.00	1.25	0.90
0.42	1.20	0.50	0.015	0.003	5.50	1.50	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 Treatment

Heat Temperatule			Start Forging Temperature			Finish Forging Temperature			Cooling Method
1020-1150ºC			1100-1120ºC			900-850ºC			Pit or Sand Cooling

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.

Q1: What is Ningbo Ningshing Precision Machinery Group Co., Ltd ?
A1: Ningbo Ningshing Precision Machinery Group Co., Ltd., formerly known as Ningbo Ningshing Special-Steel Group Co., Ltd., is the leading distributor of Special Steel, and also a professional mold base maker in China. Our business involves special steel trading, machining processing, mold base making, heat treatment, CNC machines manufacturing.


Q2: Are you a manufacturer or a trader? 
A2: For Special Steel, we are the one of the leading distributors and service center in China. 9 warehouses with over 50,000 tons of regular stock. Our workshop has various kinds of equipments for sawing, milling, grinding, drilling etc.
For mold base, we are a professional manufacturer, with 24 sets of CNC machines, 3 axis and 5 axis, CMM for inspection. We produce medium-large sized mold base for plastic injection mold and die casting die.


Q3: How do you control the quality of steels?
A3: Firstly, we have very close and deep relationship with Chinese Prime Mills, choose supplier carefully, and regard them as the long term business partner. Based on the long term cooperation, we concentrate on special steel business and expand the market step by step. Secondly, we have own technical center which is formed by the experienced engineers and technicians whom ever worked for prime mills. We control the quality in production process, in-out warehouse.


Q4:: Which kind of processing can you do?
A4: We do machining processing like cutting, milling, grinding, turning, peeling, drilling, CNC machining. Meanwhile, we do vacuum heat treatment for die and mold.