Determination of flow stress behavior of materials is a critical aspect of understanding and predicting behavior of materials during manufacturing and use. However, accurately capturing the flow stress behavior of a material at different strain rates and temperatures can be challenging. Non-uniform deformation and thermal gradients within the test sample make it difficult to match test results directly to constitutive equations that describe the material behavior. In this study, we have tested AISI 9310 steel using a Gleeble 3500 physical simulator and Digital Image Correlation system to capture transient mechanical properties at elevated temperatures (300°C – 600°C) while controlling strain rate (0.01 s -1 to 0.1 s -1 ). The data presented here illustrate the benefit of capturing non-uniform plastic strain of the test specimens along the sample length, and we characterize the differences between different test modes and the impact of the resulting data that describe the flow stress behavior.

This paper discuss recent developments in mesh belt heat treating systems used in the production of automotive fasteners. Methods for heat treating threaded fasteners have evolved significantly over the last 20 years as low-capacity shaker hearth, rotary hearth, and plate-belt systems are replaced by soft handling mesh belt heat treatment systems. Design innovations for improving the accuracy of tempering furnace tolerance bands and integrating inline zinc phosphate removal systems are discussed along with their respective benefits.

A study on the microstructural evolution of a Ni-base superalloy (Allvac 718plus) was conducted to better understand how solutionizing temperature affects the final microstructure of solutionized and aged test samples. Four different solutionizing temperatures were used to obtain different fractions of gamma prime (γ’) and delta (δ) phase precipitates. This paper describes the solutionizing treatments and presents and analyzes the results of SE-SEM, EBSD, EDS, and XRD testing.

This paper examines the causes of distortion in heat treated 1080 steel parts and the influence of quenchants and quenching temperature. A comparison of parts produced using a different oil and different quench temperatures shows that a significant improvement can be achieved in distortion with only minor grain growth and a slight reduction in hardness.

This work investigates the cooling performance of different salt solutions and quench bath parameters. The results show that increasing quenchant temperature can stabilize the vapor film, while the presence of various additives and the use of agitation can hasten its collapse. Ionic solutions containing NaCl, Na2SO4, NaOH, and NaNO2 were found to inhibit the vapor blanket at 35°C and improve cooling power. Adding salt-forming solutions promoted a more homogeneous cooling with high values of heat flux over most of the cooling cycle.

A variety of test systems have been developed to determine the cooling characteristics of quenchants. Although current test standards specify cylindrical probes for measuring quenchant temperatures and cooling rates, this review concerns the development, implementation, and potential of test systems that use ball probes instead. It assesses the strengths and limitations of different types of ball probes and describes prototype test systems that leverage ball probe capabilities while compensating for inherent weaknesses.

This paper presents the results of a study on the cooling performance of hot oil and molten salt quench media. It describes the tests performed, analyzes the results, and interprets the findings. It explains how the heat extraction mechanism in hot oil differs from that of NaNO2 eutectic mixtures and how it translates to differences in cooling rate, spatial uniformity, and hardness in quenched steel parts.