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This product is the key component of diesel engine exhaust system - exhaust pipe middle section, using high-pressure die-casting process of one-piece molding, designed to meet the high thermal load, high corrosion resistance and lightweight diesel engine needs. The product highly integrates multiple functions such as high temperature exhaust gas guidance, aftertreatment system interface, sensor installation and heat insulation protection, etc., with compact structure and excellent dimensional accuracy. Through heat-resistant die-casting alloy material and precise cooling runner design, it can withstand the high temperature and thermal shock of exhaust gas while realizing significant weight reduction, providing efficient and reliable exhaust gas transmission solutions for commercial vehicles, off-road machinery and marine diesel engines.
Technical Parameters
| parameter term | Technical indicators |
|---|---|
| casting pressure | 80-130 MPa (high pressure die casting, real time closed loop control) |
| Mold temperature control | 200-320℃ (multi-point temperature control, accuracy ±5℃) |
| material grade | Heat-resistant die-cast aluminum alloy (e.g. A356-T6, Al-Si10-Mg) / Heat-resistant stainless steel die-cast (optional, as specified by the customer) |
| Heat-resistant aluminum alloy tensile strength | ≥250 MPa (room temperature), ≥180 MPa (300°C) |
| Heat-resistant stainless steel tensile strength | ≥450 MPa (room temperature) |
| yield strength | ≥200 MPa (aluminum alloy) / ≥300 MPa (stainless steel) |
| elongation | ≥3% (aluminum alloy) / ≥25% (stainless steel) |
| Operating Temperature Range | -40°C to +650°C (≤350°C for aluminum alloys, with insulation or cooling) |
| Dimensional accuracy | Class CT6 (ISO 8062 to CT5 for flange mounting surfaces and sensor holes) |
| Flange flatness | ≤0.10mm/100mm (deformation control in hot condition) |
| surface treatment | High temperature resistant coating / Ceramic insulation coating / Passivation treatment (optional) |
| Sealing requirements | Leak rate ≤ 0.5 mL/min @ 200kPa (Helium Mass Spectrometry/Gas Tight Inspection) |
| Thermal fatigue life | ≥ 500 thermal cycles (room temperature ↔ 650°C, ramp rate ≥ 50°C/min) |
Quality Assurance System
Certified Endorsement:
- Conforms to IATF 16949 quality management system standards for the automotive industry
- ISO 9001 Quality Management System Certification
- ISO 14001 Environmental Management System Certification
Process Control:
- Closed-loop monitoring of the die casting process: real-time feedback of injection speed, boost pressure and mold temperature distribution.
- Metallurgical quality control of aluminum/steel liquids: spectral composition analysis, gas content detection, assessment of deterioration effects
- Thermal balance management of the mold: multi-point temperature monitoring and automatic cooling adjustment to control thermal stress and deformation.
- Optimized release agent spraying: ensures smooth release of complex runner structures without residue
Testing Standards:
- 100% Coordinate Inspection: Accuracy of flange mounting surface, sensor interface and connecting orifice ≤0.05mm
- X-ray/CT non-destructive testing: Determination of internal porosity, shrinkage, and cracking, in accordance with ASTM E505
- 100% Gas Tightness Test: Simulates operating pressure and temperature and automatically determines leakage rate.
- Thermal fatigue test: Cyclic thermal shock validation to ensure no cracking failures
- Metallographic Organization Inspection: Grain size, precipitated phase morphology control to ensure high temperature performance
- Cleanliness testing: Particle size and quantity control to avoid clogging of the aftertreatment system
application scenario
Diesel engines for heavy commercial vehicles
Suitable for 6L-16L displacement heavy-duty diesel engines, used to connect exhaust manifolds with after-treatment systems (SCR, DPF). The die-cast aluminum alloy solution with integrated water cooling or heat-insulating coating meets the light weight (40%~50% weight reduction compared with cast iron) while enduring the exhaust heat load and improving the fuel economy of the whole vehicle.
Off-road diesel engines
Widely used in excavators, loaders, tractors and other construction and agricultural machinery. The high-pressure die-casting structure has excellent anti-vibration fatigue performance, adapts to the continuous thermal shock under severe working conditions, and the corrosion-resistant surface treatment guarantees the reliability of outdoor all-weather operation.
Marine Diesel Engine
It is used in the exhaust system of medium and high speed marine main engine and power generation auxiliary engine. Heat-resistant stainless steel die-casting solution has excellent resistance to salt spray corrosion and high temperature oxidation, with stringent air tightness requirements, to ensure the long-term stable operation of marine power systems in the marine environment.
Diesel units for power generation
Suitable for fixed and emergency diesel generator sets. High-precision flange processing ensures the sealing of the exhaust system, reduces exhaust back pressure, optimizes engine combustion efficiency, and ensures the economy and stability of continuous power output.
Specialty Vehicle Power Systems
Applied to military tactical vehicles, armored vehicles and other high-performance diesel engines. Passing the severe thermal shock and vibration tests, it meets the environmental adaptability requirements of military standards, and its lightweight design helps to improve mobility and payload.
Technical Highlights
Development of heat-resistant die-casting alloys
For the complex thermal conditions in the middle section of the exhaust pipe, A356-T6 and special Al-Si-Cu-Mg heat-resistant aluminum alloys are preferred, and through micro-alloying and optimization of the heat treatment process, the 300℃ high-temperature tensile strength is improved to more than 180MPa. For 650℃ high temperature applications, high pressure die casting of heat-resistant stainless steel (such as CF8, CF8M), taking into account the molding accuracy and heat-resistant performance.
Integrated cooling runner design
For areas with high thermal loads, water-cooled or oil-cooled channel structures can be integrated and molded in one piece through the die-casting process. Cooling medium circulation can effectively reduce the wall temperature by 150~200℃, which significantly improves the applicability of aluminum alloy solutions and reduces the risk of thermal stress and thermal fatigue.
Topology optimization and lightweight construction
Based on CFD flow field analysis and finite element thermal structure coupling optimization, reasonable arrangement of reinforcement and variable cross-section transition, under the premise of ensuring airtightness and rigidity to achieve a weight reduction of 15%~25%. the runner inner wall is optimized by the hydrodynamic, reducing the exhaust resistance, and improving the engine power output.
High precision flange and sealing surface machining
The flange mounting surface adopts a clamping composite processing technology, flatness ≤ 0.10mm, roughness Ra ≤ 1.6μm, with metal gaskets or graphite gaskets, to ensure that the exhaust system is leak-free for a long time, and to meet the harsh sealing requirements of the National VI/Euro VI and Tier 4 emission regulations.
High temperature resistant anti-corrosion coating system
Multi-layer protection solutions are developed for different working conditions: aluminum alloy solution adopts high-temperature resistant ceramic coating (temperature resistance ≥800℃) or aluminum-silicon coating, and stainless steel solution adopts passivation + high-temperature antioxidant coating. Neutral salt spray test ≥ 500 hours and high-temperature cyclic oxidation test to ensure full life cycle corrosion protection.
Full Process Digital Manufacturing
From CAE simulation of mold flow path (ProCAST/Flow-3D), real-time data acquisition on die casting island, to online SPC monitoring on machining automated production line, we realize the whole process quality traceability. Key process parameters (ejection curve, mold temperature distribution, vacuum) are bound to the unique ID of the product to ensure consistency and reliability of high-volume supply.
Advantages over traditional cast iron solutions
| comparison dimension | High Pressure Die Casting Aluminum Solutions | High Pressure Die Casting Stainless Steel Solutions | Conventional cast iron program |
|---|---|---|---|
| unit weight | Weight reduction from cast iron 40%~50% | Weight reduction from cast iron 30%~40% | standard of reference |
| Dimensional accuracy | CT6-CT7 | CT6-CT7 | CT8-CT9 |
| surface quality | Release state Ra 3.2-6.3μm | Release state Ra 3.2-6.3μm | Cast roughness |
| heat-resistant temperature | ≤350°C (cooling aid can be upgraded) | ≤800°C | ≤650°C |
| production efficiency | Fast beat for large quantities | Faster tempo for high volume | Slow pace, high volume of machining |
| integrated function | Cooling channels, sensor holders can be integrated | Cooling channels, sensor holders can be integrated | lack of functionality |
| reprocess | Minor machining | Minor machining | Large quantity of machining |
Recommended conclusions
High-pressure die-cast aluminum alloy or heat-resistant stainless steel exhaust pipe midsection isDiesel engine in lightweight, high precision, integration of clear demand, and production of large quantitiesThe advanced technology path in the scenario. Through the selection of heat-resistant materials, cooling structure integration and precision molding process, while meeting the requirements of high-temperature reliability, airtightness and durability of diesel engines, it achieves significant weight reduction and function integration, and helps energy saving and emission reduction of the engine and optimization of the cost of the whole life cycle.
Manufacturing & Services
Ningbo Hexin Molding Co., Ltd. has rich experience in aluminum alloy casting and precision machining, and is able to provide reliable manufacturing solutions for core engine components. The company has a perfect production system, covering mold development, casting molding, precision machining and post-treatment process.
To meet the needs of different engine platforms, the company can provide customized development services, including structural optimization design, material selection and mass production support. At the same time, we support a variety of surface strengthening and functional treatments to meet the needs of different working conditions.
quality control
The company has established a stable quality management process to control the whole process of raw materials, casting process and machining accuracy. We ensure the reliability and consistency of our products under high load conditions through a number of testing methods, such as dimensional testing, performance testing and durability verification.
For more product information or customized development, welcome to contact with Contact Us .
