Please explain the differences regarding the materials mentioned below
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May I ask: what are the differences between 38CrMoALA and 42CrMoE, and what are the differences between 30Cr13 and 3Cr13?
1. 38CrMoAlA is a specialized nitrided steel that is commonly used in components such as machine tool spindles. 2. “E” denotes high-quality steel. 42CrMoE is a material specifically designed for piston rods; it is not only a high-quality carbon alloy steel but has also been remelted, making it an electroslag remelted steel. 3. The imported Japanese alloy structural steel 30cr13: Standard: JIS. Chemical composition: Carbon (C): 0.26–0.34; Silicon (Si): 0.17–0.37; Manganese (Mn): 0.40–0.70; Sulfur (S): allowable residual content ≤ 0.025; Phosphorus (P): allowable residual content. This steel is used for shafts, piston components, and other similar parts. 4. 3Cr13: Standard: GB/T 1220-1992. ● Characteristics and applications: It has a higher hardness after quenching compared to 2Cr13, and is used for tools, nozzles, valve seats, valves, etc. ●Chemical composition:
Carbon C: 0.26–0.35
Silicon Si: ≤1.00
Manganese Mn: ≤1.00
Sulfur S: ≤0.030
Phosphorus P: ≤0.035
Chromium Cr: 12.00–14.00
Nickel Ni: Allowance of up to ≤0.60
● Mechanical properties:
Tensile strength σb (MPa): After quenching and tempering, ≥735
Conditional yield strength σ0.2 (MPa): After quenching and tempering, ≥540
Elongation δ5 (%): After quenching and tempering, ≥12
Reduction of area ψ (%): After quenching and tempering, ≥40
Impact energy Akv (J): After quenching and tempering, ≥24
Hardness: After annealing, ≤235 HB; after quenching and tempering, ≥217 HB
● Heat treatment specifications and microstructure:
Heat treatment specifications: 1) Annealing: slow cooling at 800–900°C or rapid cooling at around 750°C; 2) Quenching: oil cooling at 920–980°C; 3) Tempering: rapid cooling at 600–750°C. Metallographic structure: The structural characteristic is martensitic.
Carbon C: 0.26–0.35
Silicon Si: ≤1.00
Manganese Mn: ≤1.00
Sulfur S: ≤0.030
Phosphorus P: ≤0.035
Chromium Cr: 12.00–14.00
Nickel Ni: Allowance of up to ≤0.60
● Mechanical properties:
Tensile strength σb (MPa): After quenching and tempering, ≥735
Conditional yield strength σ0.2 (MPa): After quenching and tempering, ≥540
Elongation δ5 (%): After quenching and tempering, ≥12
Reduction of area ψ (%): After quenching and tempering, ≥40
Impact energy Akv (J): After quenching and tempering, ≥24
Hardness: After annealing, ≤235 HB; after quenching and tempering, ≥217 HB
● Heat treatment specifications and microstructure:
Heat treatment specifications: 1) Annealing: slow cooling at 800–900°C or rapid cooling at around 750°C; 2) Quenching: oil cooling at 920–980°C; 3) Tempering: rapid cooling at 600–750°C. Metallographic structure: The structural characteristic is martensitic.
30Cr13 and 3Cr13 are both types of stainless steel; 3Cr13 is the old GB designation, while 30Cr13 is a type of martensitic stainless acid-resistant steel. It is generally used for making cutting tools, nozzles, valves, and valve seats.