Core Viewpoint - The 1J117 precision alloy demonstrates high strength and excellent dimensional stability, making it suitable for critical components in high-precision applications such as gears and positioning parts [1][4]. Mechanical Properties - The yield strength (σy) of 1J117 is approximately 1050–1250 MPa, and the tensile strength (σb) is around 1200–1500 MPa, providing reliable load-bearing capacity for key components [3]. - Elongation (δ) is about 12–18%, indicating moderate ductility, while hardness (HRC) ranges from 52 to 58, which is beneficial for fatigue life after high-precision machining [3]. - Fatigue limit under 2×10^6 cycles is approximately 450–600 MPa, influenced significantly by surface roughness and heat treatment [3]. - Thermal stability is maintained with strength reduction of less than 5% during short-term heat treatment at 350–500°C, ensuring good dimensional stability [3]. - The alloy exhibits stable wear and corrosion resistance due to the synergistic effects of chromium and nickel, with surface treatments enhancing actual lifespan [3]. Standards and Testing - The dual standard system of American and national standards enhances traceability in quality control during design and manufacturing processes [4]. - Mechanical performance testing follows ASTM E8/E8M and GB/T 228.1 standards, ensuring consistency in on-site inspection and factory release [5]. - Heat treatment and process specifications reference AMS 2700 and AMS 2750, ensuring traceability in temperature measurement [5]. Cost and Supply Chain Management - The use of mixed market data sources, such as LME for global price fluctuations of nickel and chromium, and Shanghai Nonferrous Metals Network for domestic pricing trends, aids in cost estimation and supply chain risk management [4][5]. - The comparison of these data sources helps in formulating robust procurement and production plans, mitigating risks associated with single-source price volatility [5]. Challenges and Considerations - There is ongoing debate regarding the trade-off between fatigue toughness and hardness in extreme high-temperature conditions, necessitating extensive comparative testing and microstructural analysis [5]. - Ignoring the impact of heat treatment and subsequent surface processing on mechanical properties can lead to fatigue or deformation risks during assembly and usage [5]. - A singular focus on strength metrics without considering ductility, processability, and thermal stability may compromise component reliability [5].

Core Viewpoint - 4J50 is a high-performance nickel-based precision alloy known for its excellent heat resistance, corrosion resistance, and mechanical properties, making it widely used in aerospace, energy equipment, and high-end manufacturing [1] Group 1: Mechanical Properties - The chemical composition of 4J50 primarily consists of nickel, with aluminum, iron, and titanium, providing good thermal stability and creep resistance [3] - Key mechanical performance parameters include: - Ultimate Tensile Strength (UTS): ≥1000 MPa (room temperature) - Yield Strength (YS): ≥850 MPa - Elongation (EL): ≥15% - Fracture Toughness (KIC): ≥120 MPa·m^(1/2) - Coefficient of Thermal Expansion: approximately 11.5×10^-6 /°C (0-650°C) - Corrosion resistance: Excellent performance in high-temperature and oxidative environments [4] Group 2: Industry Standards - The production and inspection of 4J50 alloy must adhere to strict industry standards, including: - ASTM B557M: Specifies tensile testing methods for metallic materials, applicable for testing UTS and elongation of 4J50 alloy - AMS 2224: Details the heat treatment processes for 4J50 alloy, ensuring consistent performance across different temperatures [4] Group 3: Material Selection Misconceptions - Common errors in material selection include: - Confusing alloy grades: 4J50 and similar grades like 4J32 have differences in composition and performance, necessitating clarity on application scenarios and performance requirements - Ignoring heat treatment effects: The mechanical properties of 4J50 are highly dependent on heat treatment; materials not properly treated may not meet performance standards - Not considering the usage environment: While 4J50 is suitable for high-temperature and high-load environments, it may not be the best choice in low-temperature or less corrosive environments [4][5] Group 4: Market Trends and Pricing - The cost of 4J50 alloy is significantly influenced by nickel price fluctuations, with the average LME nickel price in 2023 being approximately $25,000 per ton, while the market price for 4J50 precision alloy is around 150-180 RMB per kilogram, showing a stable growth trend [5] - The exceptional mechanical properties and broad application scenarios of 4J50 precision alloy make it an important material in high-performance engineering fields, with future prospects expected to expand due to technological advancements and changing market demands [5]