Basic Info.
Model NO.
A8 Air Hardening
Standard
AISI, ASTM, DIN, JIS, GB, BS
Composition
Stainless Steel Scrap
Special Use
High-strength Steel Plate, Wear Resistant Steel, Mold Steel
Application
Tool Steel Bar
Trademark
An steel, Bao steel, Wu steel
Product Description
1 H21 Steel Introduction:
Tungsten hot work tool steels are of different types, namely, H21 to H26 types. These hot work tool steel have similar characteristics to that of high speed tool steel. The primary alloying elements in tungsten hot work tool steel include tungsten, chromium, carbon, and vanadium. They are resistant to distortion when they are air hardened, and have higher hardening temperature when compared to chromium hot work tool steel. Breakage of the tungsten hot work tool steel can be reduced if they are preheated to operating temperature before use. Thermal shock resistance and toughness of these hot work tool steel can be improved by reducing the carbon content.
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2 H21 Steel Applications:
H21 hot work tool steel is particularly useful for hot forging and blanking dies and punches for making nuts, bolts and other similar small components. Dies, cores, inserts, pins, etc for the die casting of copper base alloys are also prime applications for this steel. Other uses include forming dies, shear blades, hot extrusion dies, mandrels, punches, die holders, ejector discs and extrusion liners.
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3 Quality Standard:
ASTM A681 Standard Specification for Tool Steel
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4 All Grades Comparison:
ASTM | AFNOR | DIN | UNI | JIS | B.S. |
---|
H21 | Z 30 WCV 9 | 1.2581 | X 28 W O9 KU | SKD5 | BH 21 |
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5 H21 Steel Chemical Composition(%):
C | Si | Mn | P | S | Cr | W | V | Ni | Cu |
---|
0.26-0.36 | 0.15-0.50 | 0.15-0.40 | 0.030 max | 0.030 max | 3.00-3.75 | 8.50-10.00 | 0.30-0.60 | 0.30 max | 0.25 max |
Smelting Option
1 EAF: Electric Arc Furnace
2 EAF+LF+VD: Refined-smelting and vacuum degassing
3 EAF+ESR: Electro Slag Remelting
4 EAF+PESR: protective atmosphere Electro Slag Remelting
5 VIM+PESR: Vacuum induction melting
Forming Option
1 Hot rolling process
2 Hot Forging: Electro-hydraulic; High-speed-hydraulic; Oil-hydraulic; Precision-forging
Heat-treatment Option
1 +A: Annealed (full/soft/spheroidizing)
2 +N: Normalized
3 +NT: Normalized and tempered
4 +QT: Quenched and tempered (water/oil)
Suface Option
1 Black Surface
2 Grounded: Bright but rough ; Not precision
3 Machining for plate: Bright and precision; Little turning scar
4 Peeled/Turned: Bright and precision; Little turning scar
5 Polished: Very Bright and precision size; Not turning scar
Other Services
1 Cutting: Small pieces
2 CNC Machine: Produce as your drawing
3 Package: Bare/Nylon/Canvas/Wooden
4 Payment:T/T, L/C, O/A(request credit)
5 Transport:FOB/CFR/CIF/DDU/DDP (train/ship/Air)
6 HEAT TREATMENT:
FORGING: Forging of the H21 steels can be performed at 1150°C (2100°F) down to 927°C (1700°F) but not below 899°C (1650°F).
ANNEALING: Pack preferably in a suitable sealed container with spent carburising mixture or cast iron chippings to prevent excessive scaling or decarburisation. Heat to 850°C / 880°C, holding at temperature for sufficient time to achieve uniformity. Cool at less than 25°C per hour to 650°C followed by air cooling. Correctly annealed the tools or parts should not exceed 248 HB.
STRESS RELIEVING: Heat to 600°C / 650°C. Hold for 2-4 hours and furnace cool.
HARDENING: Before heat treatment, sufficient machining should be carried out to remove surface decarburisation. Hardening should be carried out in controlled atmosphere furnaces or
neutral salt baths. Preheat slowly to 800°C / 850°C then transfer to a bath or furnace at
1120°C / 1170°C allowing sufficient time for uniform heating. Quench into warm oil or salt bath
operating at 520°C / 540°C. In the latter case ensure that the tools are allowed to equalise before
completing the quench by cooling in air.
TEMPERING: Tempering should be carried out immediately after proper completion of the quenching operation. Heat to within the 560°C / 675°C range soaking for two to three hours according to section. A second tempering cycle of similar duration is strongly recommended and care should be taken to ensure that the tools are allowed to cool to room temperature al least 50°C higher than that which the tools may be expected to achieve in service. The curve given indicates
typical hardness values obtained on oil quenching from 1160°C and double tempering.
7 Mechanical Properties:
Properties | Metric |
---|
Hardness, Rockwell C | 40.0 - 55.0 |
Bulk modulus | 140 GPa |
Poisson's ratio (25°C) | 0.27-0.30 |
Elastic modulus | 190-210 GPa |
8 Welding:
H21 hot work tool steel can be welded.
9 Mill′s test certificate:
EN 10204/3.1 with all relevant data reg. chem. composition, mech. properties and results of testing.
Address:
Floor17, Xinlian Building, Wuxi, Jiangsu, China
Business Type:
Manufacturer/Factory, Trading Company
Business Range:
Construction & Decoration, Metallurgy, Mineral & Energy
Management System Certification:
ISO 9000
Company Introduction:
Zhongtong Weiye Special Steel Co., Ltd. is a professional and reputable steel manufacturer and exporter in Wuxi city, China. Wuxi is close to Shanghai, enjoys excellent geographic location and convenient water, land and air transportation. Wuxi become the biggest stainless steel sheet, plate and coil supply Center in China. Zhongtong Weiye as one of the largest stock-holder and manufacturers supply a complete range of Stainless steel, pipes, galvanized products, bars, strips, angle steel, nickel alloy, super alloys and other related products. The material is all famous brand including Shanxi Taigang Iron& Steel CO, . Ltd (TISCO), Zhangjiagang Pohang (ZPSS), Shanghai(BAO STEEL), Ningbo (Baoxin) etc. The company has a modern indoor warehouse, with nearly a thousand varieties in stock that is ready for same day dispatch from our warehouses. Products are mainly exported to Europe, America, Southeast Asia, the Middle East and other countries and regions. Generally, our products are widely applied in construction, bridge, car manufacturing, electrical installation and mining. We have won recognition from our clients due to our excellent credit and services. Zhongtong Weiye Special Steel Co., Ltd. Follows the tenet of "quality of survival, integrity and development". We commit to sell quality products and make quick delivery to our customers. We would like to use high quality products and excellent service to develop a bright future with our clients.
Different kinds of products are available in our company. We′re pleased to get your Inquiry and we will reply you as soon as possible. We stick to the principle of "quality first, service first, continuous improvement and innovation to meet the customers" for the management and "zero defect, zero complaints" as the quality objective.