Search Results for distortion

This article discusses the implementation of a stationary induction hardening process for crankshafts and camshafts and the measures taken to maximize production rates while controlling part distortion.

This article demonstrates how FEA-based tools are used to model residual stress and distortion in a full-float truck axle induction hardened and cooled at different rates. The effect of cooling rate on axial displacement is discussed.

Engineers at the Ford Motor Co. are using integrated computational materials engineering (ICME) tools, allowing them to accurately simulate the heat treatment of gears and predict phase transformation kinetics and distortion.

This study looks at whether adding an annealing step to the heat treating process has an effect on residual stress and distortion on hypoid gear sets. Test results indicate that the annealing heat treatment introduced between gear set soft cutting and case carburizing helped to minimize distortion.

A new method to control distortion in difficult-to-quench geometries addresses the nonuniform cooling inherent in most gas quenching processes. This article describes the development of a controlled gas quenching prototype unit design and its operation. The prototype unit constructed was able to achieve great control within the temperature range of 400 to 100°C, using varying rates of temperature change.

The second article in this series looks at materials testing, microstructural evaluation, mechanical testing, and residual stress and distortion using the DANTE Controlled Gas Quenching process.

A new welding process known as hybrid induction arc welding (HIAW) or high deposition arc welding (HiDep) uses a hybrid approach to reduce—or even eliminate—weld distortion and greatly increase productivity. Operating directly in front of the arc welding torch, a portable induction coil heats the surfaces of the weld to, or near, the melting point. Heat generated by the welding arc is primarily used to melt the welding wire. This novel process operates at speeds two to four times faster than conventional arc welding and substantially reduces weld distortion.

4D high-pressure gas quenching ensures uniform heating and quenching for precise, repeatable results while reducing distortion. This article describes the process and equipment for 4D high-pressure gas quenching and gives some examples.

This article focuses on five common reasons for distortion and cracking during heat treatment and recommended remediations: (1) Nonuniform and uncontrollable heat transfer during heating and cooling; (2) Structural changes during phase transformation; (3) Residual stresses in the part that occur due to forming, welding, or machining before heat treatment; (4) Macro or micro steel structure; and (5) Fixturing and loading errors.

Tests conducted on vacuum carburized and quenched shafts identify variables that increase distortion and the magnitude of residual stresses.

Proper specification, measurement, and control of annealing furnace atmospheres are critical to reduce sooting, oxidation, sticking, and distortion. This article describes how to effectively design and utilize a nitrogen-hydrogen annealing atmosphere.

One of the most recent success stories for thermal spray in the automotive industry involves the development of plasma transferred wire arc (PTWA) for aluminum engine blocks. Driven by the demand to increase fuel efficiency, automakers are placing emphasis on decreasing overall vehicle weight as well as improving engine efficiency by reducing internal friction losses. The surface structure of the composite coating created by the PTWA process promotes favorable lubrication, low friction, wear resistance, improved heat transfer, and decreased bore distortion in engine block cylinders.

Computer modeling is used in the design and development stages of induction hardening to optimize the process and to improve component quality including hardness, beneficial stress distributions, and reduced distortion.

Martempering involves cooling steel from the austenitizing temperature and rapidly cooling into either specially formulated petroleum oil or a molten salt bath with a specific composition to a temperature slightly above the martensite start (Ms) transformation temperature of the steel. Martempering is performed to reduce distortion problems that may be encountered with conventional quenching methods. This article, adapted from the latest ASM Handbook on quenching and quenchants, describes suitable steels for martempering and variables that influence the process.

This article explains why defining gas quenching in terms of bar pressure no longer applies and how a new definition based on heat transfer and cooling rate leads to a better understanding of which steels and what cross-sections can be hardened via gas quenching.

Industry 4.0 is an emerging technology trend in the manufacturing arena that emphasizes the connectivity of physical and digital process across product development cycles. This article presents some examples of how Industry 4.0 will affect heat treating operations.

The Center for Heat Treating Excellence (CHTE) was founded with the goal of bringing the industrial sector and university researchers together to find solutions to real-world problems. The Center, located at Worcester Polytechnic Institute (WPI) in Massachusetts, has 19 members from all areas of industry working together with WPI researchers to improve both heat treat and thermal processing methods worldwide. This article describes some of the current CHTE research projects.

This article compares heat treat processes and furnace types that are typically used to harden gears.

Neutron-based imaging and measurement techniques are an ideal complement to x-ray methods for characterizing additively manufactured materials and components. This article presents examples showing how neutron radiography and residual strain measurements reveal the internal structure and stress distributions in highly engineered turbine blades produced by additive processes. It also discusses the development of neutron characterization tools at ORNL and a recent effort in which they were used to evaluate stress-relief treatments for large-scale metal AM structures.

Data obtained from thru-process profiling is used to calculate performance against specification, investigate process problems, and optimize the heat-treating process.