precision forging SCM440 alloy steel forgings

precision forging SCM440 alloy steel forgings

SCM440

Japanese alloy structural steel grade

SCM440 is a common steel grade for producing high-strength fasteners. The product has the advantages of stable composition, low harmful elements, high steel purity, small decarburization layer, and few surface defects. It is easy to spheroidize annealing and low cold forging cracking rate during use. The heat treatment quality is stable and the hardness is uniform. It is widely used in engines, molds and other industries.

Chinese name SCM440

Material name Alloy structural steel

Grade Japanese grade

Corresponding to 42crmo4

Material name: Alloy structural steel

Grade: SCM440 (Japanese grade, see standard JIS G4053-2008, similar to Chinese grade 42CrMo)

Corresponding: 42crmo4

Characteristics and application range:

It is a medium hardenability steel with good strength and good comprehensive mechanical properties after heat treatment, good processability and high yield rate. The maximum operating temperature is 427℃. Can be used as turbine fasteners.

Features and applications

1. Good hardenability, can be deep hardened instead of surface hardened like the anti-saw locks on the market

2. Less tendency to temper brittleness

3. Good high temperature processability, beautiful after processing

4. Good weldability

5. Good impact absorption performance, there will be a rebound feeling when the hammer hits it, and it cannot be violently destroyed. Advantages:

(1). Good processability

(2). Good impact absorption performance

(3). Easy to weld

Chemical composition

C 0.38-0.43

Si 0.15-0.35

Mn 0.60-0.85

P ≤0.03

S ≤0.03

Cu ≤0.30

Ni ≤0.25

Cr 0.90-1.20

MO 0.15-0.30

Ni≤0.25

Cu≤0.30

Mechanical properties

Tensile strength σb (MPa): ≥1080(110)Yield strength σs (MPa): ≥930(95)

Elongation δ5 (%): ≥12

Sectional reduction ψ (%): ≥45

Impact energy Akv (J): ≥63

Impact toughness value αkv (J/cm²): ≥78(8)

Hardness: ≤217HB

Sample size: The blank size of the sample is 25mm

●Heat treatment specification and metallographic structure:

Heat treatment specification: 880℃, 1h oil quenching, 650～680℃, 2h tempering, air cooling.

Metallographic structure: tempered martensite.

Heat treatment process

Annealing No.1 "760±10℃ annealing, furnace cooling to 400℃ air cooling.

HB220-230

Normalizing No.4 860±10℃ normalizing, air cooling after leaving the furnace.

Quenching+tempering No.5 840±10℃ quenching in water or oil (depending on the complexity of the product shape), 680-700 degrees tempering. HB<217

Quenching+tempering No.6 840±10℃ quenching in oil, then tempering at 470 degrees. HRC41-45

Quenching+tempering No.7 840±10℃ quenching in oil, then tempering at 480 degrees. HRC35-45

Quenching+tempering No.8 850℃ quenching in oil, then tempering at 510 degrees. HRC38-42

Quenching+tempering No.9 Quenching at 850℃, then tempering at 500℃. HRC40-43

Quenching+tempering No.10 Quenching at 850℃, then tempering at 510℃. HRC36-42

Quenching+tempering No.11 Quenching at 850℃, then tempering at 560℃. HRC32-36

Quenching+tempering No.12 Quenching at 860℃, then tempering at 390℃. HRC48-52

Company Introduction:

Qinhuangdao Zhongwei Precision Machinery Co., Ltd. was established in 1997. It is a professional manufacturer of forgings engaged in the manufacture and processing of automotive parts, marine gearbox accessories, and engineering machinery accessories. It can forge copper alloys, titanium alloys, aluminum alloys, carbon steel, stainless steel, high-temperature alloys and other materials. The company covers an area of ​​more than 10,000 square meters and has a standard factory building of 5,000 square meters. It has a complete set of advanced production technologies and equipment from mold design, development, parts manufacturing and processing. It has multiple die forging production lines mainly based on 4000T, 2500T, 1600T, 1000T, and multiple auxiliary production lines. The annual output is 15,000 tons. It is exported to more than 20 countries and regions including Germany, the United States, the United Kingdom, France, Russia, etc.