Search Results for surface hardness

Ultrasound backscattering enables direct determination of the interface between two materials with different microstructures, including different grain sizes.

The Center for Heat Treating Excellence (CHTE) at Worcester Polytechnic Institute (WPI) in Massachusetts is conducting a cutting-edge research project aimed at measuring the surface hardness and case depth on carburized steels for process verification and control. The results will enable companies to improve the quality of heat-treated products faster and more cost-effectively. Nondestructive techniques being evaluated initially include eddy current, meandering winding magnetometer (MWM), Barkhausen noise testing, and alternating current potential drop.

In this study, 316L stainless steel samples were plasma nitrided for 64 h at 370-420 °C then subjected to surface hardness and pitting corrosion testing. The results show that interstitial hardening with nitrogen significantly improved the surface hardness as well as the pitting corrosion resistance of the austenitic stainless steel.

Vacuum solution nitriding is a promising technique for increasing the surface hardness, load-bearing capability, and fatigue strength of martensitic stainless steels without sacrificing corrosion resistance. This article examines the effects of nitriding pressure and temperature on surface nitrogen content and case depth in four martensitic stainless steels.

This article provides an update on a three-year three research project by the Center for Heat Treating Excellence aimed at establishing nondestructive techniques for measuring surface hardness and case depth on carburized steels for process verification and control.

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

An examination of a bearing failure due to mismatched and incomplete flame hardening shows the need to work with heat treaters for proper selection and application. The article includes a case study of a large bearing raceway that failed due to incomplete austenitization.

Understanding the forces behind decarburization is the first step toward minimizing its detrimental effects. This article reviews decarburization basics and results of experimental work on spring steels.

An ultrafast, efficient industrial-scale boriding process can drastically reduce costs, increase productivity, and improve the performance and reliability of a variety of machine parts. This article describes a novel, environmentally friendly technology that enables treating thousands of industrial components in one batch, without creating solid or liquid waste and gaseous emissions.

Low-temperature surface hardening of stainless steel by means of gaseous processing provides a high degree of tailorability of the hard surface case without affecting corrosion resistance. This article covers the fundamental and technological aspects of the process and examines the effect of different LTSH treatments on 304 and 316 austenitic stainless steel.

As a regular contributor to the HTPro eNewsletter, Professor Induction answers a wide variety of questions regarding induction heating and heat treating. This column addresses control of quenching temperatures and affect on induction hardening results.

In this article, the authors demonstrate the use of simulation software to optimize low-pressure carburizing (LPC) processes for high-alloy steels with strong carbide-forming elements.

Active screen plasma nitriding and nitrocarburizing are relatively new processes in which a plasma discharge is applied to a metal screen surrounding the workload, generating highly reactive gas species that flow to the component surface. The active screen also radiates heat, resulting in a uniform temperature throughout the load. This article provides an overview of the two processes and presents examples of their use on stainless steel piston rings (nitriding) and 4142 and 1045 steels (nitrocarburizing).

Magnetic Barkhausen noise analysis is a nondestructive test method used since the 1980s to evaluate conditions in a variety of steel components. Primary applications include detection of thermal damage induced during grinding and evaluation of case depth in case-hardened parts. This article briefly describes its use for measure case depth and pros and cons of the using the technique for that purpose.

Induction heating is used to produce high quality, reliable aerospace components as well as unique combinations of engineering characteristics.

Advanced materials engineering is being used to solve component life cycle improvement challenges in extremely harsh working conditions. This article discusses examples from various industries where new materials and surface modifications are used to extend the useful life of engineering components and equipment.

Modern, high quality induction heat treating equipment must be readily available and flexible enough to allow for easy retooling and reprogramming to process a variety of parts. This article focuses on the technical revolution taking place in induction heating, which for the first time enables preprogramming of induction equipment to change frequency and power during the heating cycle in the same manner manner as machinists have been programming CNC machines for years. This is illustrated through a case study of induction hardening a shaft-like component.

Accurate and continuous dew point measurement is key to maintaining the atmosphere required to achieve high quality and consistency of sintered products in powder metallurgy processing.

High strength, corrosion-resistant Ferrium C64 is the culmination of a rigorous design process that bypassed extensive physical experimentation—delivering a carburizable steel with unmatched capability.

Boriding is performed by diffusing boron atoms into a metal surface and allowing the boron to react with elements present in the substrate to form metal-boride compounds. Upon diffusing enough boron into the surface, a metal-boride compound layer with high hardness precipitates and grows below the surface of the part. This article discusses boriding of ferrous alloys, including a new deep case boriding method that produces wear layer depths comparable to competitive processes such as carburizing, nitriding, thermal spray coatings, and hardfacing.