Carburizing

2005 ◽  
pp. 163-226
Keyword(s):  
Shot Peening ◽  
Surface Hardening ◽  
Selection Process ◽  
Cold Treatment ◽  
Vacuum Carburizing ◽  
Gear Teeth ◽  
Heat Treat ◽  
Gas Atmosphere ◽  
Gas Carburizing ◽  
Core Hardness

Abstract Gas (atmosphere) carburizing is the de facto standard by which all other surface hardening techniques are measured and is the emphasis of this chapter. Initially, the chapter describes the process and equipment for gas carburizing. This is followed by sections discussing the processes involved in quenching, hardening, tempering, recarburizing, and cold treatment of carburized and quenched gears. Next, the chapter reviews the selection process of materials for carburized gears and provides information on carbon content, properties, and core hardness of gear teeth. The problems associated with carburizing are then covered, followed by the processes involved in heat treat distortion and shot peening of carburized and hardened gears. Information on grinding stock allowance on tooth flanks to compensate for distortion is also provided. The chapter further discusses the applications of carburized and hardened gears. Finally, it reviews vacuum carburizing and compares the attributes of conventional gas carburizing and vacuum carburizing.

scholarly journals Increase in Fatigue Limit of Gears by Compound Surface Refining Using Vacuum Carburizing, Contour Induction Hardening and Double Shot Peening

2002 ◽  
Vol 45 (2) ◽  
pp. 290-297 ◽  
Author(s):  
Katsuyuki MATSUI ◽  
Hirohito ETO ◽  
Katsuya YUKITAKE ◽  
Yoshitaka MISAKA ◽  
Kotoji ANDO
Keyword(s):  
Fatigue Limit ◽  
Shot Peening ◽  
Induction Hardening ◽  
Vacuum Carburizing ◽  
Compound Surface

scholarly journals Stress Relaxation Behavior of Cavitation-Processed Cr–Mo Steel and Ni–Cr–Mo Steel

2019 ◽  
Vol 9 (2) ◽  
pp. 299
Author(s):  
Kumiko Tanaka ◽  
Daichi Shimonishi ◽  
Daisuke Nakagawa ◽  
Masataka Ijiri ◽  
Toshihiko Yoshimura
Keyword(s):  
Residual Stress ◽  
Stress Relaxation ◽  
Shot Peening ◽  
Compressive Residual Stress ◽  
High Pressures ◽  
Relaxation Behavior ◽  
Material Surface ◽  
Stress Relaxation Behavior ◽  
Gas Atmosphere ◽  
New Processing

Cr–Mo steel and Ni–Cr–Mo steel have higher strength and hardness than carbon steel, and they are occasionally used in harsh environments where high temperatures and high pressures are simultaneously applied in an oxidizing gas atmosphere. In general, in order to improve the fatigue strength of a material, it is important to impart compressive residual stress to the material surface to improve crack resistance and corrosion resistance. Conventionally, the most famous technique for imparting compressive residual stress by surface modification of a material is shot peening processing. However, in shot peening processing, there is concern that particles adhere to the surface of the material or the surface of the material becomes rough. Therefore, in this study high temperature and high-pressure cavitation was applied and the material surface was processed at the time of collapse. A theoretical and experimental study on a new processing method giving compressive residual stress was carried out. In the present study, we will report stress relaxation behavior due to the heat of cavitation in processed Cr–Mo steel and Ni–Cr–Mo steel.

Analysis of Surface and Subsurface Layers after Shot Peening of Various Aluminium Alloys

2010 ◽  
Vol 89-91 ◽  
pp. 53-58
Author(s):  
Sebastjan Žagar ◽  
Janez Grum
Keyword(s):  
Surface Layer ◽  
Crack Initiation ◽  
Residual Stresses ◽  
Surface Integrity ◽  
Shot Peening ◽  
Aluminium Alloys ◽  
Surface Hardening ◽  
Hardened Layer ◽  
Operating Pressure ◽  
Subsurface Layers

In the paper two aluminium alloys, i.e. 6082 and 7075, which were cold hardened by shot peening under different conditions, are treated. Surface hardening was carried out with S170 steel shot of the same diameter, particle hardness being 56 HRC. Other conditions were the operating pressure, mass flow, which provide different Almen intensities. The hardened layer was described by surface integrity. Macroscopic and microscopic analyses consisted in analyses of hardened profiles of hardness, and residual stresses in the thin surface layer. Research results indicated that there were significant differences among the characteristics chosen to describe surface integrity and that they had an important influence on the final condition of the surface layer. With too severe settings of the peening parameters, the surface properties got worse because of damages, which resulted in crack initiation and growth of the existing cracks.

Vacuum Carburizing in a Pit Furnace: A 21st Century Solution to Large Component Case Hardening

2021 ◽  
Author(s):  
Don Marteeny ◽  
Maciej Korecki ◽  
Agnieszka Brewka-Stanulewicz
Keyword(s):  
Cost Effective ◽  
Process Time ◽  
Vacuum Furnace ◽  
Case Hardening ◽  
Vacuum Carburizing ◽  
Gas Carburizing ◽  
Increasing Process ◽  
Vacuum Furnaces ◽  
Component Case

Abstract Low pressure carburizing (LPC) is a proven, robust case hardening process whose potential is only limited by the style and size of vacuum furnace. Today, LPC is typically used in horizontal vacuum furnaces where the opportunity to carburize large parts is limited. In this paper we present a new adaptation of the technology in large pit type vacuum furnaces, capable of opening to air at elevated temperature. This underscores the potential of LPC to carburize larger, more massive parts in a clean, effective and efficient process. The result is quality casehardened parts without the undesirable side effects of atmosphere gas carburizing such as the use of a flammable atmosphere, reduced CO and NOx emissions, no intergranular oxidation, and limited retort life. Another significant advantage is decreased process time. The case study presented here shows that eliminating furnace conditioning and increasing process temperature can significantly reduce cycle durations by nearly three times and cut utility costs in half. Under these conditions, a return on investment (ROI) is in the neighborhood of 1 – 2 years is possible, making LPC in a pit style furnace a cost-effective solution than traditional atmosphere gas carburizing technologies.

The effect of the cementite phase on the surface hardening of carbon steels by shot peening

2010 ◽  
Vol 527 (21-22) ◽  
pp. 5852-5857 ◽  
Author(s):  
W.B. Lee ◽  
K.T. Cho ◽  
K.H. Kim ◽  
K.I. Moon ◽  
Y. Lee
Keyword(s):  
Shot Peening ◽  
Surface Hardening ◽  
Carbon Steels ◽  
Cementite Phase

Effect of Si content on surface hardening of Al–Si alloy by shot peening treatment

2011 ◽  
Vol 509 ◽  
pp. S265-S270 ◽  
Author(s):  
K.T. Cho ◽  
S. Yoo ◽  
K.M. Lim ◽  
H.S. Kim ◽  
W.B. Lee
Keyword(s):  
Shot Peening ◽  
Surface Hardening ◽  
Si Content

scholarly journals Surface hardening of IF steel by plasma nitriding: Effect of a shot peening pre-treatment

2014 ◽  
Vol 260 ◽  
pp. 168-178 ◽  
Author(s):  
Ana P.A. Manfridini ◽  
Cristina Godoy ◽  
J.C. Avelar-Batista Wilson ◽  
Marcos V. Auad
Keyword(s):  
Shot Peening ◽  
Surface Hardening ◽  
Plasma Nitriding ◽  
If Steel ◽  
Pre Treatment
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