A large-scale diesel engine gas valve and its manufacturing method

Abstract

The invention relates to the technical field of large-scale marine diesel engine air valve manufacturing. The invention provides a large-scale diesel engine air valve and a manufacturing method thereof, which includes an air valve disc made of 3J40 alloy, and has the following organizational structure: the grain size reaches Ultra-fine grains above grade 10, lamellar phases are uniformly distributed at the grain boundaries of ultra-fine grains and Ni-poor Cr-Al-Ce particle phases are evenly distributed in the matrix, and the thickness of a single sheet of the lamellar phase is less than 140nm , the nickel-poor Cr-Al-Ce particle phase diameter is less than 10 μm. Pre-treatment: 3J40 alloy rods are subjected to solution treatment, the temperature of solution treatment is 1000-1050°C, the time of solution treatment is 50-70min, oil cooling; sequentially undergo electric upsetting, supplementary heat treatment, heat preservation treatment, mold The air valve is obtained by forging, and the final post-treatment: carry out aging heat treatment on the air valve, the temperature of aging heat treatment is 770-790°C, the time of aging heat treatment is 16~18h, and air cooling after aging heat treatment. The invention solves the technical problem of how to simultaneously improve the comprehensive mechanical performance and vibration damping performance of a large-scale diesel engine valve.

Description

technical field

[0001] The invention relates to the technical field of large-scale ship air valve manufacturing. Background technique

[0002] The large prime mover is the heart of a large ship, and its superior performance is the key to realizing the excellent transportation capacity of the ship. Among them, the low-speed diesel engine valve (belonging to the large-scale diesel engine valve) is a key component of the combustion chamber intake / exhaust of a large diesel engine, and its performance seriously affects the reliability, power and service life of the diesel engine. During the working process of the diesel engine, the high-temperature gas produces a huge burst pressure and carries strong corrosive substances. At the same time, the alternating load imposed by the valve spring and various moving parts makes the valve exposed to high temperature, impact, wear and corrosion for a long time In the harsh environment, it is easy to cause the valve to be damaged due to fai...

Examples

Embodiment 1

[0043] The 3J40 alloy in this embodiment contains the following essential elements in terms of mass percentage: Cr: 39.2%, Al: 3.32%, Fe:: 0.12%, Ce: 0.2%, Si: 0.03%, Mn: 0.10%, S : 0.010%, P: 0.0033%, C: 0.018%, and the balance is Ni.

[0044] Manufacture diesel engine valves with a rod diameter of 67mm, a total length of 1230mm, and a disc diameter of 327mm. 3J40 alloy is given to make electric upsetting bar material, and the blanking length is 2560mm. Solution treatment is carried out before electric upsetting, and the 67mm bar is subjected to solution heat treatment at a temperature of 1020°C*60min oil cooling, and oil cooling. Static recrystallization occurs during the solid solution process, due to incomplete solid solution The lamellar phase and nickel-deficient Cr-Al-Ce granular phase retard the grain growth caused by the migration of static recrystallized grain boundaries, and at the same time provide heterogeneous nucleation due to the rare earth element Ce inclus...

Embodiment 2

[0056] The 3J40 alloy in Example 2 contains the following essential elements in mass percent: Cr: 39.56%, Al: 3.39%, Fe:: 0.14%, Ce: 0.12%, Si: 0.061%, Mn: 0.010%, S : 0.003%, P: 0.006%, C: 0.022%, and the balance is Ni.

[0057] The raw material of the alloy in Example 2 has undergone a series of operations in manufacturing and processing the valve (including two solid solution treatments and one aging heat treatment in the manufacturing steps of the patented valve). The pre-treatment solid solution treatment is 1000°C*50min oil cooling, the supplementary heat preservation treatment is 1000°C*20min+1020°C*25min, and the post-treatment aging heat treatment is 770°C*16h air cooling. The valve surface and rod material of the air-taking valve were subjected to scanning experiments and surface energy spectrum detection. The cut samples were electrolytically corroded with 10% oxalic acid solution for 5 seconds. to observe. The measured result: Figure 6 It is a 20,000 times scan...

Embodiment 3

[0059] The 3J40 alloy in Example 3 carries out the gas valve manufacturing process flow, including the following essential elements in mass percentage: Cr: 39.23%, Al: 3.35%, Fe:: 0.26%, Ce: 0.15%, Si: 0.061%, Mn: 0.010%, S: 0.002%, P: 0.005%, C: 0.015%, and the balance is Ni.

[0060] The solution treatment before electric heading is 1050℃*70min oil cooling. The unique rare earth element Ce of 3J40 alloy, after adding Ce element in the alloy, Ce element has the effect of refining the grain, and will generate fine spherical high melting point cerium oxide or cerium oxysulfide inclusions to replace some large low melting point inclusions segregated At the grain boundary, the Ce inclusions segregated at the grain boundary provide heterogeneous nucleation cores and increase the nucleation rate, so the austenite grains are refined and the grain boundaries increase. At the same time, the alloy The lamellar phase and the Ni-poor Cr-Al-Ce granular phase are not completely dissolved...

technical field

[0001] The invention relates to the technical field of large-scale ship air valve manufacturing. Background technique

[0002] The large prime mover is the heart of a large ship, and its superior performance is the key to realizing the excellent transportation capacity of the ship. Among them, the low-speed diesel engine valve (belonging to the large-scale diesel engine valve) is a key component of the combustion chamber intake / exhaust of a large diesel engine, and its performance seriously affects the reliability, power and service life of the diesel engine. During the working process of the diesel engine, the high-temperature gas produces a huge burst pressure and carries strong corrosive substances. At the same time, the alternating load imposed by the valve spring and various moving parts makes the valve exposed to high temperature, impact, wear and corrosion for a long time In the harsh environment, it is easy to cause the valve to be damaged due to fai...

Examples

Embodiment 1

[0043] The 3J40 alloy in this embodiment contains the following essential elements in terms of mass percentage: Cr: 39.2%, Al: 3.32%, Fe:: 0.12%, Ce: 0.2%, Si: 0.03%, Mn: 0.10%, S : 0.010%, P: 0.0033%, C: 0.018%, and the balance is Ni.

[0044] Manufacture diesel engine valves with a rod diameter of 67mm, a total length of 1230mm, and a disc diameter of 327mm. 3J40 alloy is given to make electric upsetting bar material, and the blanking length is 2560mm. Solution treatment is carried out before electric upsetting, and the 67mm bar is subjected to solution heat treatment at a temperature of 1020°C*60min oil cooling, and oil cooling. Static recrystallization occurs during the solid solution process, due to incomplete solid solution The lamellar phase and nickel-deficient Cr-Al-Ce granular phase retard the grain growth caused by the migration of static recrystallized grain boundaries, and at the same time provide heterogeneous nucleation due to the rare earth element Ce inclus...

Embodiment 2

[0056] The 3J40 alloy in Example 2 contains the following essential elements in mass percent: Cr: 39.56%, Al: 3.39%, Fe:: 0.14%, Ce: 0.12%, Si: 0.061%, Mn: 0.010%, S : 0.003%, P: 0.006%, C: 0.022%, and the balance is Ni.

[0057] The raw material of the alloy in Example 2 has undergone a series of operations in manufacturing and processing the valve (including two solid solution treatments and one aging heat treatment in the manufacturing steps of the patented valve). The pre-treatment solid solution treatment is 1000°C*50min oil cooling, the supplementary heat preservation treatment is 1000°C*20min+1020°C*25min, and the post-treatment aging heat treatment is 770°C*16h air cooling. The valve surface and rod material of the air-taking valve were subjected to scanning experiments and surface energy spectrum detection. The cut samples were electrolytically corroded with 10% oxalic acid solution for 5 seconds. to observe. The measured result: Figure 6 It is a 20,000 times scan...

Embodiment 3

[0059] The 3J40 alloy in Example 3 carries out the gas valve manufacturing process flow, including the following essential elements in mass percentage: Cr: 39.23%, Al: 3.35%, Fe:: 0.26%, Ce: 0.15%, Si: 0.061%, Mn: 0.010%, S: 0.002%, P: 0.005%, C: 0.015%, and the balance is Ni.

[0060] The solution treatment before electric heading is 1050℃*70min oil cooling. The unique rare earth element Ce of 3J40 alloy, after adding Ce element in the alloy, Ce element has the effect of refining the grain, and will generate fine spherical high melting point cerium oxide or cerium oxysulfide inclusions to replace some large low melting point inclusions segregated At the grain boundary, the Ce inclusions segregated at the grain boundary provide heterogeneous nucleation cores and increase the nucleation rate, so the austenite grains are refined and the grain boundaries increase. At the same time, the alloy The lamellar phase and the Ni-poor Cr-Al-Ce granular phase are not completely dissolved...

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