Search Results for case depth

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.

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.

Process optimization and optimal component performance can be achieved when multiple variables are measured and studied as a whole. In the investigation described in this article, fatigue performance of AISI 8620 H steel was characterized as a function of carburization case depth, hardness, residual stress, and retained austenite to demonstrate that an optimized carburization process could be engineered to meet specific application requirements.

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.

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.

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.

Plasma nitriding is very effective in removing the passive layer of chromium oxide formed naturally on the surface of stainless steel, but controlling the kinetics is key for optimal results.

Preventive multi-frequency testing using eddy current ensures heat-treated parts meet specifications.

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

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

An advanced, patented probe sensor provides early detection of water infrastructure problems caused by corrosion and harsh atmospheric conditions. Designed to detect graphitization in active pipelines, it identifies areas at risk of major failures early on. By using indirect methods like GIS mapping, in-situ soil resistivity testing, and structure-to-soil potential measurements, high-risk zones can be pinpointed. Once these areas are identified, the probe assesses the severity and depth of graphitization, providing a comprehensive evaluation of the pipeline’s condition. This allows for the implementation of effective corrosion management strategies, including cathodic protection systems, to prevent critical failures. This article describes the sensor system and provides a case study of its use. The technology received the 2024 Engineering Materials Achievement Award from ASM International.

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.

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.

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.

Manufacturing data together with heat treating knowledge can be synthesized with physics and data-based modeling approaches in a closed loop to provide insight for improving process efficiency and product quality for overall reduction in operating and energy costs. This article provides case studies of data analytics for coil batch annealing and batch carburizing.

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.

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.

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.

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

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.