Selecting the Right Vacuum Pump Oil Starts with Knowing Your Pump

August 7, 2018 / FEATURED NEWS, MANUFACTURING HEAT TREAT, MANUFACTURING HEAT TREAT NEWS, VACUUM PUMPS GAUGES VALVES, VACUUM PUMPS GAUGES VALVES TECHNICAL CONTENT

Source: VAC AERO International

Vacuum furnace heat treaters know that one of the most critical parts of their system is the pump oil, but it may be a bit overwhelming trying to determine which is the right kind of oil is needed. Selecting the correct vacuum pump oil starts with knowing your pump.

“‘Oil’ is a bit of a misnomer because modern pump oil technology has evolved well beyond the original distilled petroleum products. There are now double- and triple-distilled oils available, as well as hydro-treated oils, low sulfur oils, silicone-based synthetic oils, and flushing oils used to clean the pump. Due to the wide variety of formulations available, these are often now referred to as pump ‘fluids’ rather than pump ‘oils’.” — VAC AERO International

“Different pump oil formulations are specifically designed for different pumps and different vacuum applications,” notes VAC AERO, and a key factor in learning how to select the correct pump oil is the understanding of vapor pressure, viscosity, and distillation methods, as well as solvent refining, hydrotreating, synthetic oil (Perfluoropolyether), flushing oil for vacuum pumps, and diffusion pump oils.

Figure 1 | Viscosities of various liquids

Before Normalizing, Pause to Assess Materials

July 31, 2018 / MANUFACTURING HEAT TREAT

Source: BluewaterThermal.com

When there is a need to provide a uniform, pearlitic structure at a microscopic level, many heat treaters turn to normalizing to increase or restore metal strength, but experts at Bluewater Thermal Solutions note the need to assess all aspects of the material before choosing this process.

“It is possible with given alloys and metals that the process may also cause a decrease in overall strength.”

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How to Know Which Softening Process to Use in Your Heat Treatment

July 17, 2018 / ANNEALING TECHNICAL CONTENT, FEATURED NEWS, MANUFACTURING HEAT TREAT, MANUFACTURING HEAT TREAT NEWS

Source: Metlab Heat Treat

When steel needs to be softened to alter ductility, toughness, or properties, or to produce a specific microstructure, a heat treater can turn to any one or combination of processes to suit the material or the application.

Metlab Heat Treat’s primer series includes a short explanation of the options available, whether it is

annealing, which “removes the internal stresses, which build up as a result of cold working and other fabrication processes;”
protective atmosphere normalizing, which “refines the grain size and enhances the uniformity of the microstructure;” or
spheroidize annealing, which “is generally done on parts which have been work hardened, to allow them to be further worked, either rolled in the case of coils, or drawn for wire.”

1.) Load of torsion bars, manufactured from 4340 steel, normalized in the vertical position to maintain straightness. Parts measure approximately 3\” in diameter by 6\’ long.

2.) 26,000 pounds of low carbon steel flat wire being prepared for spheroidize annealing. Spheroidize annealing is an intermediate processing step to allow the wire to be further rolled to a smaller gage without cracking.

Photo credit: Metlab Heat Treat

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What’s Going on Inside Your Heat Treated Part?

July 10, 2018 / FEATURED NEWS, HARDNESS TESTERS TECHNICAL CONTENT, MANUFACTURING HEAT TREAT, MANUFACTURING HEAT TREAT NEWS

Source: Gear Technology

It’s no secret to heat treaters that not all methods work well on all parts and specifications. It’s also a hard fact that false readings can result when applying hardness measuring systems, therefore, says Charles D. Schulz of Gear Technology, “critical service parts often require a few ‘sacrificial lambs’ to be processed along with the production parts.”

“I cannot emphasize enough that if you are not cutting up parts or coupons you do not know what is really happening during your thermal processing.” — Charles D. Schulz

Photo credit: Gear Technology

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Tool Steel Potential Dependent Upon Heat Treating

June 26, 2018 / FEATURED NEWS, MANUFACTURING HEAT TREAT, MANUFACTURING HEAT TREAT NEWS

Source: L&L Special Furnace

With its unique ability to be used in the shaping of other materials, tool steel, which includes a variety of carbon and alloy steels, is a particularly valuable property for tool manufacturers as well as manufacturers of components and parts that require the same degree of distinctive hardness, resistance to abrasion and deformation, and ability to hold a cutting edge at elevated temperatures.

The three-phase process of heat treating tool steel — annealed, austenite, and martensite — ensures the tool retains these qualities, achieves intended functionality, and meets performance specifications. In addition,

“The phases that define the process of heat treating tool steel alter the microstructure of the steel itself. Observable under a microscope, heat treatment rearranges the atoms of the iron, carbon, and any other metal components, which serves to give the final material specifically desired properties.” — L&L Special Furnace

Multiple factors can influence the final product, including the appropriate hardening and tempering temperatures depending on the type of steel.

This table provides general recommendations for the appropriate hardening and tempering temperatures based on steel type, as well as the recommended type of quench process. — L&L Special Furnace

“Heat treating tool steel does more than adding significant value to the treated material—it makes the use of the tool steel possible. Without properly applied heat treating, tools simply wouldn’t work or couldn’t even be made. Modern metallurgical engineering is essential to the production and manufacturing of tool steel and all of its applications.” — L&L Special Furnace

Photo credit (main image): Youtube.com and caption: “Visual indication of tool steel phase change to austenite when heat treating. Small pools of iron are forced from the steel as the volumetric change takes place and small amounts of carbon are burned off.”

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Clarity and Accuracy in Heat Treat Specifications Ensures Quality Processing

June 19, 2018 / FEATURED NEWS, MANUFACTURING HEAT TREAT, MANUFACTURING HEAT TREAT NEWS

Source: Paulo Learning Center

Heat treaters strive to deliver parts that meet industry and manufacturers’ specifications with precision, but too often the information they get from customers is inadequate, unclear or incorrect. This article from Paulo’s Learning Center provides 7 points of data that will help a metallurgist treat parts to stand up to the manufacturer’s intended application, including:

making sure materials are clearly identified
specifying the process required
noting prescribed hardness tolerance
identifying case depth tolerance
sharing the right amount of information
providing correct hardness scales
identifying inspection points

Photo credit: Paulo Learning Center

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Binder Removal in Vacuum Sintering

June 12, 2018 / FEATURED NEWS, MANUFACTURING HEAT TREAT, MANUFACTURING HEAT TREAT NEWS, SINTERING POWDER METAL NEWS, VACUUM FURNACES TECHNICAL CONTENT

Source: TAV: The Vacuum Furnaces Blog

Heat Treat Today previously posted Parts 1 and 2 of this series on vacuum sintering. Part 1 focused on the two processing steps of debinding and sintering. Part 2 addressed primarily the vacuum sintering furnace itself. This installment analyzes the process and variables involved with binder removal.

Andrea Alborghetti, technical manager of TAV Vacuum Furnaces and contributor to the company’s blog, provides an analysis of burning vs capturing binders, addressing advantages as well as problems that may arise and how to execute control in the process, as in this example:

“One thing that is worth clarifying is that the flames usually seen on the outlet of kilns that use combustible gases (hydrogen, for example) as the process gas, were not originally designed to burn the binder disassociation residues to reduce emissions to the legal limits. Rather, it is solely for disposing of the emitted hydrogen safely, thus avoiding hazardous, potentially explosive atmospheric concentrations being created outside of the kiln.”

Read more for further analysis of binder removal, including discerning the type of residue found with your process: “Perfect Vacuum Sintering Step by Step #3”

Binder Removal in Vacuum Sintering Read More »

Seven Types of Annealing, and Why Bearing Manufacturers Should Turn to Spheroidization

June 5, 2018 / ANNEALING TECHNICAL CONTENT, FEATURED NEWS, MANUFACTURING HEAT TREAT

Sources: Machine Manufacturing; Knergize.com

Heat treating more often than not includes the process of annealing in order to induce precise softness; to alter ductility, strength, or properties; or to produce a definite microstructure. Because of the wide variety of steels and metal alloys, it is important for heat treaters to match the correct annealing process with the steel grade and to the application of the parts being treated.

Machine Manufacturing has provided a summary of the annealing process and listed seven types of annealing, describing the process and the objectives for each. Included in the list are:

Complete Annealing
Isothermal Annealing
Incomplete Annealing
Spherification Annealing
Diffusion, or Uniform, Annealing
Stress Relief Annealing
Recrystalization Annealing

And to take the analysis into more specific types of annealing, over at Knergize.com, Dr. S.B. Sarkar discusses Spheroidized Annealing and its benefit to bearing manufacturers, describing the metallurgical science behind the process, noting the need to adhere to international standards and specifications, and addressing equipment management and quality control of the process.

Photo credit

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Feasibility Studies for Aerospace Applications Should Review Heat Treatment

May 29, 2018 / AEROSPACE HEAT TREAT, AEROSPACE HEAT TREAT NEWS, FEATURED NEWS

Source: Precipart

When designing for manufacturability (DFM) for aerospace applications, should a design team commission a comprehensive feasibility study? In this article from Precipart, which designs and manufactures high precision custom gears and mechanical components for the medical technology, aerospace and industrial sectors, read about application-specific requirements, concerns with production tooling, and tolerance of materials for post-fabrication processes, including heat treatment:

key specifications of a gear or motion control system
potential design issues that may occur throughout the life of a device; for example, how heat treatment, among other post-fabrication processes,
recommendations to address performance issues in various environments and conditions

Feasibility Studies for Aerospace Applications Should Review Heat Treatment Read More »

The Pros and Cons of Gas and Ion (Plasma) Nitriding

May 22, 2018 / FEATURED NEWS, MANUFACTURING HEAT TREAT, MANUFACTURING HEAT TREAT NEWS, NITRIDING TECHNICAL CONTENT

Source: AHTcorp.com

The compound zone acts as a ceramic skin protecting the metal underneath from corrosion. (Photo credit: Advanced Heat Treat Corp)

Engineers considering the advantages and disadvantages of surface treatments typically have a usable lifespan, surface hardness, and fatigue strength in mind. As a process, both gas and ion (plasma) nitriding avoid the issues involved with coatings and achieve similar metallurgical properties, and the compound zone increases corrosion resistance. But what are other areas in which the two processes can be compared, and what are their differences? It’s good to know, particularly since the latter could significantly make a direct impact on the end product.

Jacob McCann, a process metallurgist with AHT Corp., provides a specific list of pros and cons of gas nitriding and ion (plasma) nitriding in our Technical Tuesday feature for today.

Photo credit: Advanced Heat Treat Corp

The Pros and Cons of Gas and Ion (Plasma) Nitriding Read More »

Technical Tuesday