Cobalt Alloy Casting

K640 is a solid solution-strengthened and carbide-strengthened cobalt-based casting superalloy, and its strength level is slightly lower than that of nickel-based casting superalloy K401. Cobalt alloy casting has excellent thermal fatigue performance, oxidation resistance and corrosion resistance at high temperature, so it is especially suitable for making gas turbine guide blades working below 1000 °C. In the long-term aging at 800 °C, the structure is stable, the casting performance is good, and it can be cast into parts such as hollow blades with complex shapes. However, due to the shortage of cobalt resources, the application is limited.

After more than ten years of precipitation, Qinhuangdao Zhongwei Precision Machinery Co., Ltd. has rich experience in the production of cobalt alloys, nickel alloys, superalloys and other castings. We expect manufacturers from all over the world to consult and negotiate business.

Product Description

Basic situation of Cobalt alloy casting

1. Implementation standards: The company strictly implements ISO9001 & TS 16949 certification.

2. Product material standards: ISO, GB, ASTM, SAE, ISO, EN, DIN, JIS, BS

3. Main processes: sand casting, silica sol investment casting, water glass investment casting,shell casting,deburring, sand blasting, machining, heat treatment, leak testing, surface treatment, etc.

4. Available materials:

Titanium alloy, carbon steel, alloy steel, stainless steel, gray iron, cast iron, cast steel, cast aluminum, cast copper, etc. can be customized according to customer requirements.

Cobalt Alloy Casting Production Process

K640 technical standard

YB/T 5248—1993 "Casting Superalloy Master Alloy"

K640 Chemical Composition

1.K640 heat treatment system: the alloy is used in the as-cast state.

2. K640 varieties, specifications and supply: round bar-shaped master alloy ingots. As-cast supply.

3. K640 smelting and casting process:

The master alloy is smelted in a vacuum induction furnace, the refining temperature is 1580°C, and the pouring temperature is 1460°C. Argon gas with a pressure of 5000-7000Pa should be introduced during pouring. The master alloy can also be smelted in an electric isolated furnace. Vacuum induction furnace or non-vacuum arc reversing furnace heavy furnace, the pouring temperature is 1450-1490 ℃, and the heating temperature of the mold shell is lower than 850 ℃. During vacuum casting, argon gas with a pressure of 5000-7000Pa is also required.

4. K640 application overview and special requirements:

The alloy has been used in an aero-engine as a guide vane. The X40 alloy similar to this alloy is widely used in foreign aviation jet engines, such as: JT3D, JT9D, JT4A, CFM56 and SpeyMK202 engine turbine blades or guide vanes are made of this alloy.

5. K640 process performance and requirements:

(1) Formability

The casting performance is better than that of austenitic stainless steel, and it can be cast into thin-walled hollow blades and other parts by investment casting.

(2) Welding performance

1) It has good welding performance with inert gas arc welding. Oxyacetylene welding is generally not used. The K640 alloy itself can be connected with K640 electrode, and the connection with other alloys should preferably use the HastelloyW alloy electrode. Before welding large parts, it is required to preheat within 371-427℃ to avoid cracking after welding. V-shaped connections are generally used, but U-shaped connections are recommended for parts that are subject to high stress.

2) When welding in a protective atmosphere, it is recommended that the weld size should not be increased from both sides, and copper blocks should not be used as lining plates.

3) When using DC isolated welding, better mechanical properties can be obtained. In order to prevent cracking, it is recommended to use the inclined electric arc back-and-forth surfacing.

(3) Heat treatment process of parts: The parts are used in the as-cast state.

Post Casting Process

1. Heat treatment: annealing, carbonization, tempering, quenching, normalizing, surface tempering

2. Processing equipment: CNC, WEDM, lathe, milling machine, drilling machine, grinder, etc.;

3. Surface treatment: powder spraying, chrome plating, painting, sandblasting, nickel plating, galvanizing, blackening, polishing, bluing, etc.

Moulds and Inspection Fixtures

1. Mold service life: usually semi-permanent. (except for lost foam).

2. Mold delivery time: 10-25 days, (according to product structure and product size).

3. Tooling and mold maintenance: Zhongwei is responsible for precision parts.

Quality Control

1. Quality control: the defective rate is less than 0.1%.

2. Samples and trial run will be 100% inspected during production and before shipment, sample inspection for mass production according to ISDO standards or customer requirements

3. Testing equipment: flaw detection, spectrum analyzer, golden image analyzer, three-coordinate measuring machine, hardness testing equipment, tensile testing machine;

4. Provide after-sales service.

5. The quality can be traced back.

Application

The alloy has excellent properties, and has the characteristics of wear resistance, corrosion resistance, high temperature resistance, and can produce various products. Cobalt alloy casting is widely used in petrochemical, metallurgy, machinery, gas turbine guide vanes, wood cutting, automobile, paper and food processing industries.