What industrial equipment components are suitable for 3D printing of high-strength alloy steel?

一,The potential of high-strength alloy steel to be 3D printed: the combination of material qualities and process benefits
The 3D printing applicability of high-strength alloy steels (e.g., martensitic aged steel 18Ni300, H13 tool steel, 4140 low-alloy steel) arises from their distinctive metallurgical characteristics and synergistic additive manufacturing techniques:
Controllability of microstructure
3D printing's "layer by layer melting rapid solidification" feature may actively regulate the size and direction of the grains in alloy steel. For example, the selective laser melting (SLM) procedure may make the grains in 18Ni300 martensitic aged steel smaller to the micrometre level. This makes the yield strength 30% stronger than typical forging methods. The Institute of Metals at the Chinese Academy of Sciences found that regulating the heat treatment process very well can stop pores from forming and make titanium alloy more than 50% more resistant to fatigue. This method can also be used to improve the grain structure of high-strength alloy steel.
The ability to make complicated structures
People often employ high-strength alloy steel to make parts that can handle very heavy loads, such turbine discs for aircraft engines and pressure vessels for nuclear power plants. In the past, manufacturing and welding had to be done separately. With 3D printing, though, you can make complicated shapes like interior hollows and conformal cooling channels all at once. NASA employs Inconel 718, a nickel-based alloy with 18% chromium and 9% molybdenum, to make rocket engine nozzles with 3D printing. The components stay structurally sound at high temperatures of 2000 °C because to a permeable cooling channel design. This is not possible with ordinary casting.
Using materials and lowering costs
Using traditional forging technology, only 50% to 70% of the material is used, but 3D printing can use more than 90%. For example, Arup has used 3D printing to make stainless steel moulds for cars. This has cut the weight of each part by 75%, the amount of steel used by 30%, and the efficiency of production by 10 times. For high-strength alloy steel like H13 tool steel, which costs 800 yuan per kilogram, using less material means big savings on costs.
二,Common use case: Industrial use of 3D printing to make high-strength alloy steel
1. Aerospace: A dual breakthrough in lightweight and high-strength aircraft engine parts. Platinum Lite makes a high-temperature alloy case for the aerospace industry utilizing GH3039 nickel-based alloy, which has 20% Cr and 13% Co. By using topology optimization design, the weight is cut by 40% while still meeting the requirements for creep resistance at a high temperature of 1000 ℃.
Parts of a spacecraft's structure: Professor Zhang Haiou's team has created the "integrated casting, forging, and milling" 3D printing technology. This technology has made high-strength aluminium alloy parts that are 500 cm long, including the landing gear and load-bearing structure of the C919 airplane. This technology does the casting, forging, and milling processes at the same time. This makes the parts twice as strong against fatigue and cuts the manufacturing time by 60% compared to traditional methods.
2. Energy and chemical industry: A guarantee of corrosion resistance and stability at high temperatures
Nuclear power tools: Shared equipment employs adhesive spraying technique to 3D print nuclear power steel (such SA-508 Gr.3 low-alloy steel) and gets rid of internal pores by hot isostatic pressing (HIP) after the fact. The components can withstand 360 °C and 17.2 MPa without corroding, which fulfills ASTM A923 criteria. This means that typical castings can last three times longer.
Oil and gas extraction: Schlumberger employs electron beam melting (EBM) technology to 3D print connectors for deep-sea drilling platforms. The connectors are made of 4140 low-alloy steel, which has 1% Cr and 0.5% Mo. Vacuum printing gets rid of impurities and makes the parts 50% tougher at -40 °C, which is what oil and gas development in the Arctic Circle needs.
3. Automotive Manufacturing: A New Way to Make Things Lightweight and Useful
Electric car battery pack: Volvo used cold spray metal 3D printing technology to make battery pack brackets. They used H13 tool steel (which has 5% Cr and 1.5% V) and a biomimetic lattice structure design. The impact energy absorption capacity has been increased, and the weight has been cut by 35%. This meets the collision safety regulations for electric vehicles.
Engine with high performance: The valve seat rings of the BMW M-series engine are made of titanium alloy (Ti-6Al-4V) that has been 3D printed. The rings are then coated with nickel-based tungsten carbide through surface laser cladding. Compared to standard powder metallurgy methods, the parts are four times more resistant to wear at temperatures of 900 °C and last eight times longer.
三,Technical Problems and Possible Solutions: Important Problems that Need to Be Solved Before Labs Can Become Factories
3D printing of high-strength alloy steel offers a lot of promise, but there are still three main problems that need to be solved before it can be used on a big scale:
Controlling costs and printing speed
It still takes 6 to 8 hours to print one large part, like an aviation engine shell. The costs of equipment depreciation and powder make the manufacturing costs 3 to 5 times higher than previous methods. The Platinum BLT-S800 multi-laser head parallel printing technology can make things three times more efficient, and the metal powder recovery technology can lower the cost of raw materials by 40%.
Control of residual stress and deformation
When high-strength alloy steel cools quickly, it can cause residual stress, which can cause parts to bend or shatter. AddUp and ECM Group worked together to create a heat treatment solution that lowers residual stress in Inconel 718 alloy parts by 70% and keeps deformation to under 0.1mm through staged annealing (500 °C insulation for 2 hours + 700 °C aging treatment for 4 hours).
Increasing the number and kinds of materials
Right now, there are only a little over ten mature 3D-printed high-strength alloy steels. These steels are hard to use in really harsh conditions, such very high temperatures (>1200 °C) and significant corrosion (as in damp H2S environments). The creation of new metal ceramic composite materials, such TiC-18Ni300, is pushing the limits of materials. It can get as hard as HRC 65, which is 50% harder than pure metals. This makes it good for making parts that won't wear out on deep-sea drilling platforms.