42C4 Lost Wax Investment Casting

Product Introduction

42C4 Medium Carbon Modulated Steel Properties

42C4 steel is medium carbon modulated steel and cold heading mold steel. The steel is moderately priced and easy to process. It can obtain certain toughness, plasticity, and wear resistance after appropriate heat treatment. Normalizing can promote tissue spheroidization and improve the cutting performance of blanks with a hardness of less than 160HBS. Tempered at a temperature of 550~570℃, the steel has the best comprehensive mechanical properties. This steel has high hardenability and is suitable for surface hardening treatments such as high-frequency quenching and flame quenching.

Application

After quenching and tempering, 42C4 lost wax investment casting is used to manufacture mechanical parts that bear medium loads and work at medium speeds, such as steering knuckles, rear axles of automobiles, and gears, shafts, worms, spline shafts, center sleeves, etc. on machine tools; After quenching and tempering at medium temperature, it is used to manufacture parts that bear high load, impact and medium speed operation, such as gears, spindles, oil pump rotors, slides, collars, etc.; after quenching and tempering at low temperature, it is used to manufacture parts that bear heavy loads. , low impact and wear-resistant parts with a physical thickness of less than 25mm on the cross-section, such as worms, spindles, shafts, collars, etc.; used to manufacture high surface hardness and wear resistance after quenching and tempering and high-frequency surface quenching Parts that are durable and have no great impact, such as gears, sleeves, shafts, spindles, crankshafts, spindles, pins, connecting rods, screws, nuts, intake valves, etc. In addition, this kind of steel is suitable for manufacturing various transmission parts that undergo carbonitriding treatment, such as gears and shafts with larger diameters and good low-temperature toughness.

42C4 Lost Wax Investment Casting Parts Performance

• Elastic mold

Elastic modulus E(20℃)/MPa 200000～211700, shear modulus G(20℃) 80800

• Heat treatment

Quenching 850℃, oil cooling; Tempering 520℃, water cooling, oil cooling. The surface quenching hardness of 40Cr is HRC52-60, and the flame quenching can reach HRC48-55.

• Nitriding treatment

42C4 steel is a nitridable steel, and the elements it contains are conducive to nitriding.

42C4 can obtain higher surface hardness after nitriding treatment.

After 42C4 quenching and tempering, the highest hardness after nitriding treatment can reach HRA72~78, that is, HRC43~55.

Nitriding workpiece process route:

Forging - annealing - rough machining - quenching and tempering - finishing - stress removal - rough grinding - nitriding - fine grinding or grinding. Since the nitride layer is thin and brittle, it requires a higher-strength core structure. Therefore, quenching and tempering heat treatment must be performed first to obtain tempered sorbate to improve the mechanical properties of the core and the quality of the nitride layer. Soft nitriding is active nitriding, and gas nitriding is more commonly used now.

• Welding

42C4 to prevent internal chilling and quenching cracks in the weld due to heat dissipation from the matrix. It is best to add normalizing after welding and before tempering. It is easy to segregate during crystallization and is sensitive to crystallization cracks (a type of thermal crack). It is easy to crack in arc craters and concave parts of the weld during welding. The carbon content is high, and it is easy to obtain a hardened structure (martensite structure) that is sensitive to cold cracks during rapid cooling. When the cooling rate in the overheated zone is high, it is easy to form hard and brittle high-carbon martensite and embrittle the overheated zone.

Welding Process

1. Welding is generally performed in the annealed (normalized) state.

2. Welding methods are not restricted.

3. Use larger linear energy and increase the preheating temperature appropriately. Generally, the preheating temperature and interlayer temperature can be controlled between 250 and 300°C.

4. Welding materials should ensure that the composition of the deposited metal is basically the same as the base metal, such as J107-Cr.

5. Quenching and tempering heat treatment should be carried out promptly after welding. If it is difficult to perform quenching and tempering in time, intermediate annealing can be performed or kept at a temperature higher than preheating for a period of time to eliminate diffusible hydrogen and soften the tissue. For products with complex structures and many welds, an intermediate annealing can be performed after a certain number of welds are welded.

Detection Systems

Copper Silica Sol Investment Casting