Designation by Standards
Brand Name | Ravne No. | Mat. No. | DIN | EN | AISI |
RAVNEX | 868 | 1.2343 Mod | X38CrMoV51 Mod | X38CrMoV51 Mod | H11 Mod |
Chemical Composition ( in weight %)
C | Si | Mn | Cr | Mo | V |
0.36 | 0.20 | 0.30 | 5.00 | 1.35 | 0.45 |
Description
RAVNEX is supreme steel grade in the group of hot work tool steels. Special production methods ensure optimal parameters in all phases of steelmaking, providing this steel grade with supreme characteristics resulting in a higher tool durability. This steel incorporates the knowledge and experience of many generations of tool steel specialists.
Applications
Above all, the RAVNEX grade is designed for die casting of light metals and alloys (aluminium and aluminium alloys), for die forging of steel and non-ferous metals (eg. Cupper) and their alloys, for extrusion of tubes, barrels and sections made of light metals and alloys, for casting and processing of various plastics, and for glass processing. Characterics: Excellent homogeneity, high cleanliness, high level of isotrophy, good workability, high impact toughness, good polishability. Advantages: Lower cost due to: Higher tool life, lower tool wear, less tool repair, less tool changes and consistent heat treatment results.
Thermal Conductivity [W/m. K] vs. Temperature
100℃ | 200℃ | 300℃ | 400℃ | 500℃ | 600℃ | 700℃ |
28.4 | 29.7 | 30.2 | 30.1 | 30.0 | 29.7 | 30.0 |
Coefficient of Linear Thermal Expansion 10-6℃-1
20-100℃ | 20-200℃ | 20-300℃ | 20-400℃ | 20-500℃ | 20-600℃ | 20-700℃ | 20-800℃ |
11.9 | 12.4 | 12.8 | 13.2 | 13.6 | 14.2 | 14.4 | 14.4 |
Soft Annealing
Heat to 800-850℃/min. 4 hours at temperature then cool slowly in furnace. This will produce a maximum Brinell hardness of 209HB.
Stress Relieving
Stress relieving to remove machining stresses should be carried out by heating to approx. 600-650℃, holding for 3 hours at temperature, followed by slow cooling in furnace. This operation is performed to reduce distortion during heat treatment and to reduce stress after machining of tools prior to dinal heat treatement of tools.
Hardening
Harden from a temperature of 980-100℃/30 min. At temperature, followed by oil, thermal bath, air, vacuum and protective atmosphere quenching.
Tempering
1st tempering: 20-30℃ over secondary peak in the tempering diagram.
2nd tempering: Tempering to a working hardness of tool.
Recommendation: 3rd tempering from 20-50℃ down to bellow the temperature of 2nd tempering.
Tempering: Slow heating up to tempering temperature is recommended, tempering tims: min. 2 hours and/or 1 hour for 20-25 mm thickness for tool.
Tempering Temperature (℃) vs. Hardness (HRC)
100℃ | 200℃ | 300℃ | 400℃ | 500℃ | 550℃ | 600℃ | 650℃ |
54 | 53 | 52 | 51.5 | 52 | 52 | 47 | 38 |
Microstructure
When annealed, the RAVNEX microstructure consists of equally distributed secondary carbides in the form of globules in a ferritic base along the whole section. To achieve such microstructure in an annealed condition, special advanced metallurgical methods are carried out in all phases of steel production. When annealed, hardness ranges between 170 and 209 HB. RAVNEX provides a uniform hardness and toughness along the entire tool cross-section. This is achieved with a uniform distribution of secondary carbides in steel, even after hardening and tempering.
Nitriding
RAVNEX is suitable for nitriding and nitrocarburizing. Surface hardness over 1000HV0.3 can be achieved by gas, plasma, or salt processes. Nitriding must be performed 20-50℃ below a previous tempering temperature, depending on the process time and temperature, to avoid loss of hardness, strength, and dimensional changes of the workpiece. Essential benefits of a hard nitrided or nitrocarburizing surface lie in an improved.
Welding
RAVNEX can be welded successfully by the MMA or GTA welding process, provided that proper precautions are taken before, during, and after welding. Laser weld repaire of smaller cracks and edges is recommended to minimize negative effects of high residual stresses in weldments and heat affected zones. GTA welding is generally performed using AISI H11 consumables. Proper weld preparation is crucial; cracks are ground out to sound steel, correct joint slope and bottom radius shall be considered. Welding can be performed in soft annealed or hardened and tempered condition. In both cases, a preheat to 350℃ is recommended. This temperature is to be maintained throughout welding. After welding, soft annealed or hardened and tempered parts are slowly cooled down to between 70 and 100℃, then soft annealed or tempered 20℃ below the last tempering temperature.
Dimensional Changes During Hardening
Temperature gradients in a workpiece during quenching often cause high stresses which cause distortion. Stress relief annealing between rough and semi-finish machining prior to hardening is recommended to limit distortion during quenching. Minimum machining allowance to account for Ravnex distortion during a correctly performed rapid quench is 0.4% of the characteristic workpiece dimension, provided that stress relief annealing has been performed.
Electrical Discharge Machining
Surfaces which aresubjected to the Electrical Discharge Machining (EDM) process must be ground or blanched ground to remove the brittle, resolidified surface layer. In additon, the material subjected to EDM must be tempered about 20℃ bellow the previous tempering temperature to give a temper to the rehardened and untempered layer underneath. Both layers are very brittle and such detrimental to die performance.
Aluminium Die Casting Tool Life
Maximum results are achieved when steel producers, tool producers and product producers combine their knowledge and experience. Technical support from production combined with sales expertise is required to service these products. We offer a vast knowledge in the production of hot work tool steels.
Wrkshp&Wrhse&Shppg
Below inspection will be done in the production.
(1) ray detection---RT;
(2) ultrasonic testing---UT;
(3) Magnetic Particle Testing-MT;
(4) penetration testing-PT;
(5) eddy current flaw detection-ET
Bozhong Group Mainly supply in forms of coil, sheet, plate, rod, bar, tube, pipe, beam, angle, flange, wire, strip, channel, etc., with various varieties, wide range of dimensions, high purity, stable chemical composition, high dimensional accuracy and excellent surface quality. The products are mainly used in the fields of industries such as automobile engineering, railway transportation, aviation, aerospace, machinery, petrochemical, energy, environmental protection, offshore, chemical, oil & gas, ilitary, power plant, nuclear power, pressure vessel, boiler equipment, mold manufacture, etc.
l steel coil
l steel plate
l steel sheet
l steel bar/rod
steel round bar
steel flat bar
steel square bar
l steel pipe/tube ( welded or seamless )
steel round pipes
steel square pipes
steel welded tubes
steel seamless tubes
l steel strip
l steel beam
l steel angle
l steel channel
l steel flange
l Steel wire
Bozhong Group can supply a variety of structural steel, high-strength steel, wear-resistant steel plate, boiler and pressure vessel steel, marine engineering and stainless steel plate in the thick steel and various European standard bars and pipes and profiles.Our global sales and service network throughout all around the world to ensure that the goods reach the customer in the shortest time.
We can follow your drawings and requirements, to provide you with oxygen cutting, plasma cutting and laser cutting and other processing services. You can also perform ultrasonic testing in accordance with EN10160 standard, EN10164 standard test Z15, Z25, Z35, weld bending detection, PWHT detection,etc.
We have ISO9001: 2000 quality management system certification, and obtain the quality certification from all the well-known certification company, including TuV / LRS / GL / CE and so on.
Special steel includes as below:
Boiler and pressure vessel steel
Pipeline steel
Bridge steel
Nuclear power steel
Structural steel
Die steel
High strength steel
Abrasion resistant steel
Weathering, corrosion resistant and fire resistant steel
High rise building steel
Shipbuilding and offshore engineering steel
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A: We are group of companies and owned manufacturer bases and trading company. We specialized in special steel which include alloy structural steel and carbon steel and stainless steel, etc. All material are with high quality and competitive price.
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