The Effects of Low Temperature Carbon Diffusion Treated Fasteners on Thread Galling Resistance

2017 ◽  
Author(s):  
Karson P. Clark
Keyword(s):  
Low Temperature ◽  
Surface Hardening ◽  
Chemical Elements ◽  
Surface Hardness ◽  
Carbon Diffusion ◽  
Initial Study ◽  
Chemical Company ◽  
Diffusion Treatment ◽  
Class 1 ◽  
Limited Scope

Kolsterising® is a low temperature carbon diffusion treatment, referred to as carburization, in which carbon is forced into the surface of metal. This results in a significant increase of surface hardness without the formation of crystalline solids or chemical elements.1 Carburization is not a coating process therefore the possibility of delamination is eliminated with the process. 2 Low temperature carbon diffusion treatment is being considered by a chemical company to possibly aid in the disassembly of higher alloy fasteners in attempts to reduce maintenance and equipment overhaul time during plant outages. This paper will explore the effects surface carburization, or carbon diffused surface hardening, has on the resistance of thread galling for B8M Class 1, B8M Class 2, and Hastelloy® C-276 fasteners.3 With the data provided from this initial study, a better understanding of the benefits low temperature carbon diffusion treated fasteners provides will be obtained. This paper has a limited scope that will utilize hand torqueing at various percentages of bolt yield to analyze the resultant clamping force of carburized fasteners in comparison to that of standard fasteners. This study is a milestone to further clarify the thread galling resistance that carburized fasteners provides.

scholarly journals Influence of Machining on Low Temperature Surface Hardening of Stainless Steel

2019 ◽  
Author(s):  
Ulli Oberste-Lehn ◽  
Andreas Karl ◽  
Chad Beamer
Keyword(s):  
Corrosion Resistance ◽  
Low Temperature ◽  
Stainless Steels ◽  
Surface Hardening ◽  
Surface Hardness ◽  
Austenitic Stainless Steels ◽  
Production Costs ◽  
Machining Process ◽  
Machining Operations ◽  
Temperature Surface

Abstract The main goal of low temperature surface hardening of austenitic stainless steels is a significant increase of surface hardness while at the same time maintaining the superior corrosion resistance of these alloys. The treatment temperature has to be low enough to achieve a precipitation free diffusion zone, yet high enough to allow sufficient diffusion depths needed for technical applications. The results are often influenced by the machining of parts prior to the surface treatment. Best results are usually achieved on solution annealed and (electro-)polished surfaces, but customer needs for certain manufacturing routes, strength considerations and overall production costs often do not allow for such additional processes. This paper shall give a basic overview on machinability of austenitic stainless steels and how different machining operations like turning, cold forming, grinding and additive manufacturing influence the result of low temperature surface hardening. Possible machining process optimizations for the different machining operations are presented in order to increase diffusion depth, surface hardness, reproducibility and corrosion resistance without altering the hardening process parameters.

scholarly journals Experimental investigation on a novel approach for laser surface hardening modelling

2021 ◽  
Vol 16 (1) ◽  
Author(s):  
L. Orazi ◽  
A. Rota ◽  
B. Reggiani
Keyword(s):  
Surface Hardening ◽  
Carbon Diffusion ◽  
Industrial Applications ◽  
Laser Surface ◽  
Simplified Approach ◽  
Laser Surface Hardening ◽  
Novel Approach ◽  
Laser Treatments ◽  
High Flexibility ◽  
Short Time

AbstractLaser surface hardening is rapidly growing in industrial applications due to its high flexibility, accuracy, cleanness and energy efficiency. However, the experimental process optimization can be a tricky task due to the number of involved parameters, thus suggesting for alternative approaches such as reliable numerical simulations. Conventional laser hardening models compute the achieved hardness on the basis of microstructure predictions due to carbon diffusion during the process heat thermal cycle. Nevertheless, this approach is very time consuming and not allows to simulate real complex products during laser treatments. To overcome this limitation, a novel simplified approach for laser surface hardening modelling is presented and discussed. The basic assumption consists in neglecting the austenite homogenization due to the short time and the insufficient carbon diffusion during the heating phase of the process. In the present work, this assumption is experimentally verified through nano-hardness measurements on C45 carbon steel samples both laser and oven treated by means of atomic force microscopy (AFM) technique.

INFLUENCE OF TIME-TEMPERATURE PARAMETERS OF LONG-DURATION EXPOSURE ON TRANSFORMATIONS IN STRUCTURAL STEELS (review)

2021 ◽  
pp. 15-23
Author(s):  
E.A. Eliseev ◽  
◽  
G.S. Sevalnev ◽  
A.V. Doroshenko ◽  
M.E. Druzhinina ◽  
...  
Keyword(s):  
Low Temperature ◽  
Chemical Elements ◽  
Structural Steels ◽  
Holding Time ◽  
Temper Brittleness ◽  
Brittleness Temperature ◽  
Temperature Range ◽  
Long Duration ◽  
Reversible Temper ◽  
Reversible Temper Brittleness

Low-temperature nitriding of steels is usually carried out in the temperature range of development of reversible temper brittleness. The holding time at these temperatures significantly exceeds the holding time during normal tempering, which can negatively affect the properties of steel. The article considers theories that explain the processes occurring in steels in the temper brittleness temperature range. It may be concluded that views linking the embrittlement of steel with alloying elements such as nickel in its content are not confirmed by the experiments; at the same time ideas based on classical views about the diffusion of chemical elements explain the processes in steel better.

scholarly journals Surface Modification of a Nickel-Free Austenitic Stainless Steel by Low-Temperature Nitriding

Metals ◽  
2021 ◽  
Vol 11 (11) ◽  
pp. 1845
Author(s):  
Francesca Borgioli ◽  
Emanuele Galvanetto ◽  
Tiberio Bacci
Keyword(s):  
Stainless Steel ◽  
Corrosion Resistance ◽  
Austenitic Stainless Steel ◽  
Low Temperature ◽  
Stainless Steels ◽  
Volume Fraction ◽  
Surface Hardness ◽  
Austenitic Stainless Steels ◽  
Surface Layers ◽  
Modified Surface

Low-temperature nitriding allows to improve surface hardening of austenitic stainless steels, maintaining or even increasing their corrosion resistance. The treatment conditions to be used in order to avoid the precipitation of large amounts of nitrides are strictly related to alloy composition. When nickel is substituted by manganese as an austenite forming element, the production of nitride-free modified surface layers becomes a challenge, since manganese is a nitride forming element while nickel is not. In this study, the effects of nitriding conditions on the characteristics of the modified surface layers obtained on an austenitic stainless steel having a high manganese content and a negligible nickel one, a so-called nickel-free austenitic stainless steel, were investigated. Microstructure, phase composition, surface microhardness, and corrosion behavior in 5% NaCl were evaluated. The obtained results suggest that the precipitation of a large volume fraction of nitrides can be avoided using treatment temperatures lower than those usually employed for nickel-containing austenitic stainless steels. Nitriding at 360 and 380 °C for duration up to 5 h allows to produce modified surface layers, consisting mainly of the so-called expanded austenite or gN, which increase surface hardness in comparison with the untreated steel. Using selected conditions, corrosion resistance can also be significantly improved.

Surface hardening of SUS304 by irradiation with a KrF excimer laser in SiH4 gas ambient

1990 ◽  
Vol 5 (2) ◽  
pp. 265-270 ◽  
Author(s):  
Koji Sugioka ◽  
Hideo Tashiro ◽  
Koichi Toyoda ◽  
Eiichi Tamura ◽  
Keigo Nagasaka
Keyword(s):  
Excimer Laser ◽  
Surface Hardening ◽  
Continuous Distribution ◽  
Surface Hardness ◽  
Laser Pulses ◽  
High Concentration ◽  
Laser Fluences ◽  
High Adhesion ◽  
Krf Excimer Laser ◽  
Si Films

Surface hardening of SUS304 resulting from the process of doping and deposition of Si by irradiation of a KrF excimer laser beam in a SiH4 gas ambient is investigated, and variations of the surface hardness are examined for different numbers of laser pulses and the laser fluences. The hardening is due to Si incorporation in high concentration. The continuous distribution of Si atoms across the surface layer suggests that a very high adhesion strength of the deposited Si films can be formed. The specific process for surface modification is referred to as laser implant-deposition (LID).

The Effect of Surface Self-Nanocrystallization on Low-Temperature Gas Carburization for AISI 316L Steel

2019 ◽  
Vol 795 ◽  
pp. 137-144
Author(s):  
Zhe Liu ◽  
Ya Wei Peng ◽  
Jian Ming Gong ◽  
Chao Ming Chen
Keyword(s):  
Stainless Steel ◽  
Elastic Modulus ◽  
Austenitic Stainless Steel ◽  
Low Temperature ◽  
Surface Hardness ◽  
Electron Probe Micro Analyzer ◽  
Gas Carburizing ◽  
316L Steel ◽  
Negative Effect ◽  
Effect Of Surface

In this work, the effect of surface self-nanocrystallization on low-temperature gas carburizing for AISI316L austenitic stainless steel has been studied. The surface ultrasonic rolling processing (SURP) was used to prepare nanostructured surface layers, and then the un-SURP and SURP samples were treated by LTGC at 470 °C for 10 h, 20 h and 30 h. In order to analyze the effect of surface self-nanocrystallization on low-temperature gas carburizing, optical microscopy (OM), atomic force microscope (AFM), scanning electron probe micro-analyzer (EPMA) and nano-indentation analyzer were used. The results show depth of SURP-induced plastic deformation layer was about 330 μm. Meanwhile, the surface hardness and elastic modulus were increased but the surface roughness decreased obviously after SURP. After low-temperature gas carburizing, according to the results of the thickness, carbon concentration, nano-hardness and elastic modulus of the carburized layer, the conclusion is that surface self-nanocrystallization carried by SURP has a negative effect on the low-temperature gas carburizing for AISI316L austenitic stainless steel and with the increase of carburizing time, the greater the adverse effect on carburizing.

Low-Temperature Carburization of the Ni-base Superalloy IN718: Improvements in Surface Hardness and Crevice Corrosion Resistance

2010 ◽  
Vol 41 (8) ◽  
pp. 2022-2032 ◽  
Author(s):  
Reza Sharghi-Moshtaghin ◽  
Harold Kahn ◽  
Yindong Ge ◽  
Xiaoting Gu ◽  
Farrel J. Martin ◽  
...  
Keyword(s):  
Corrosion Resistance ◽  
Low Temperature ◽  
Crevice Corrosion ◽  
Surface Hardness ◽  
Base Superalloy
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