We typically start the New Year off by focusing on new technologies throughout the thermal-processing industry in our January issue. With that in mind, let’s begin 2023 by looking at some interesting technological developments that have come across my inbox in the past nine months.


Heat Treatment Allows 3D-Printed Metals to Withstand Extreme Conditions

A new heat treatment developed by Massachusetts Institute of Technology (MIT) trans-forms the microscopic structure of 3D-printed metals, making them stronger and more resilient in extreme thermal environments. The technique could make it possible to 3D-print high-performance blades and vanes for power-generating gas turbines and jet engines. This could lead to new designs with improved fuel consumption and energy efficiency.

The MIT scientists found a way to improve the structure of 3D-printed alloys by adding an additional heat-treating step, which transforms the as-printed material’s fine grains into much larger “columnar” grains. The team’s new method is a form of directional re-crystallization – a heat treatment that passes a material through a hot zone at a precisely controlled speed to meld a material’s many microscopic grains into larger, sturdier and more uniform crystals.

In a study, the MIT team adapted directional recrystallization for 3D-printed nickel-based superalloys, metals that are typically cast and used in gas turbines.

You can learn more about the process here.


induction heating

A thin rod of 3D-printed superalloy is drawn out of a water bath and through an induction coil, where it is heated to temperatures that transform its microstructure, making the material more resilient. Image courtesy of Dominic David Peachey/MIT


Solution for Welding Thick Metal Sections

A novel dynamic beam laser (DBL) technology will enable single-pass laser welding of metals 25-50 mm thick. The DBL’s megahertz-level frequencies, which expose a broader set of parameters for enhanced control of laser welding processes by using unlimited beam shaping and up to 20 mm of focus position, influence how much control laser welders have over keyhole and melt-pool dynamics.

Civan Lasers and AMET collaborated to develop the laser welding system. “DBLs are similar to electron-beam technology in its ability to wobble the beam in megahertz regimes. However, DBLs can do so without requiring a vacuum environment,” said Dr. Eyal Shekel, CEO of Civan.

The unique capabilities of the DBL enable thick-metal laser welding for the first time, ac-cording to the collaborating companies. The advantages of DBL technology include eliminating the need for beveling and reducing HAZ and distortion along with higher welding speeds. The companies will present the first system, which is being produced in AMET’s Idaho factory, in February 2023.


Solution for Welding Thick Metal Sections

A novel dynamic beam laser (DBL) technology will enable single-pass laser welding of metals 25-50 mm thick. The DBL’s megahertz-level frequencies, which expose a broader set of parameters for enhanced control of laser welding processes by using unlimited beam shaping and up to 20 mm of focus position, influence how much control laser welders have over keyhole and melt-pool dynamics.

Civan Lasers and AMET collaborated to develop the laser welding system. “DBLs are similar to electron-beam technology in its ability to wobble the beam in megahertz regimes. However, DBLs can do so without requiring a vacuum environment,” said Dr. Eyal Shekel, CEO of Civan. 

The unique capabilities of the DBL enable thick-metal laser welding for the first time, ac-cording to the collaborating companies. The advantages of DBL technology include eliminating the need for beveling and reducing HAZ and distortion along with higher welding speeds. The companies will present the first system, which is being produced in AMET’s Idaho factory, in February 2023. 


AMET

AMET’s expertise in designing and manufacturing welding systems makes the company an ideal partner to build a Civan DBL-based system that will offer a turnkey welding solution for thick metal sections. Image courtesy of AMET


Melting Technology Replaces Blast Furnaces

Primetals Technologies and RHI Magnesita are working together to develop a new green steel technology to replace blast furnace plants. The Smelter is a furnace powered by electrical energy and used for melting and final reduction of direct reduced iron (DRI). Operated together with a direct reduction plant and an LD converter (BOF), the Smelter produces hot metal for steelmaking and liquid slag that can be used in the cement indus-try. The conventional BF-LD converter route results in almost 2 tons of CO2 per ton of liquid steel. According to Primetals Technologies, the new technology will reduce CO2 emissions by a factor of six, to 0.33 tons of CO2 per ton of liquid steel.


Primetals Image courtesy of Primetals Technologies


The refractory material protects the furnace shell by containing hot metal at tempera-tures of at least 2732°F (1500°C). Consisting of bricks, it expands when heated and en-dures extremely high temperatures. The performance of the refractory material is deter-mined by several factors, such as size, quality, mechanical furnace design and cooling solutions.

The collaboration has already been in effect for some time and several simulations have been executed. Primetals Technologies and RHI Magnesita say the Smelter is ready for market.


Extreme Heat from Renewable Electricity

Coolbrook, an engineering technology company based in Finland, is working on technol-ogy that can produce the extreme heat needed for industrial processes from renewable electricity sources. The company says it has found a way to achieve temperatures of up to 1700°C through a novel form of electrification.

According to Coolbrook, its RotoDynamic Heater (RDH) is the only electric process heating technology able to reach 1700°C without burning fossil fuels. In RDH, air, nitro-gen and process gases are heated to high temperatures, and the heated gas is used outside the heater to replace the burning of fossil fuels in process heating. The company says the technology can replace fossil-fired furnaces and kilns with electric heating in industrial processes.

RDH brings together space science, turbomachinery and chemical engineering. With aerodynamic action achieved through a rotating blade flow, RDH can replace conven-tional fossil-fired furnaces and kilns in industrial heating processes by directly imparting the shaft’s mechanical energy to the heated gas to provide process heat for the produc-tion of steel, cement and other chemicals. An electric motor drives the rotors, and air, nitrogen or process gases are heated to extremely high temperatures.

Coolbrook says the technology can be retrofitted to existing production plants and will be ready for large-scale use in 2024. Read about it here.


Coolbrook

Image courtesy of Coolbrook



EBW Breakthrough for Thick-Section Materials

Sheffield Forgemasters announced a breakthrough in the industrialization of electron-beam welding (EBW) for thick-section materials. Using EBW, the company weld-joined two 200-mm-thick (8-inch-thick), 3-meter-diameter (9-foot-diameter) forged vessel sections of nuclear-grade steel. The weld, equivalent to approximately 10 meters (32 feet) in length, was completed in a single pass and in a dramatically short timeframe. The weld was completed in 140 minutes with no reportable defects shown in preliminary nondestructive testing (NDT). A weld of this kind would typically take months and include numerous stages of NDT and heat treatment, according to U.K.-based Sheffield Forge-masters.


Sheffield Forgemasters

PImage courtesy of Sheffield Forgemasters


Sheffield Forgemasters aims to incorporate advanced fabrication techniques, which will provide significant savings on both processing time and cost through the potential of EBW over the more traditional method of tungsten inert gas welding for thick-section pressure vessels. The EBW process uses local vacuum and a high-power electron gun, which penetrates the vessel material with an electron beam, to melt and fuse the two components together in one pass rather than building up multiple layers of weld filler wire.