Influence of Grinding Conditions on Residual Stress Profiles after Induction Surface Hardening

2005 ◽  
pp. 346-351
Author(s):  
Janez Grum
Keyword(s):  
Residual Stress ◽  
Surface Hardening ◽  
Grinding Conditions ◽  
Stress Profiles ◽  
Induction Surface Hardening

Influence of Grinding Conditions on Residual Stress Profiles after Induction Surface Hardening

2005 ◽  
Vol 490-491 ◽  
pp. 346-351
Author(s):  
Janez Grum
Keyword(s):  
Surface Layer ◽  
Residual Stresses ◽  
Surface Hardening ◽  
Physical And Mechanical Properties ◽  
Grinding Wheel ◽  
Workpiece Material ◽  
Heat Effects ◽  
Grinding Conditions ◽  
Induction Surface Hardening ◽  
Hardened Surface

Induction surface hardening creates very desirable residual stresses in the hardened surface layer. Residual stresses are always of a compressive nature and are usually present to the depth of the induction-hardened layer. By the appropriate selection of grinding wheel and grinding conditions and taking into account the physical and mechanical properties of the workpiece material very favourable compressive residual stresses in the hardened surface layer can be retained. How is it possible to assure a desirable surface and surface layer quality after induction hardening and fine grinding? Finding an answer to this question requires a very good knowledge of the process of grinding on the micro-level as well as knowledge of mechanical and heat effects acting on the layer of the workpiece including the type and condition of the grinding wheel. An allinclusive consideration of the numerous influences of the kind and condition of the tool on the changes on the surface and in the surface layer of the workpiece in the given machining conditions is described by the term “surface integrity”.

Instability Parameter for Machined Parts

1983 ◽  
Vol 105 (3) ◽  
pp. 133-136 ◽  
Author(s):  
A. Israeli ◽  
J. Benedek
Keyword(s):  
Residual Stress ◽  
Residual Stresses ◽  
Single Point ◽  
Machining Parameters ◽  
Machining Processes ◽  
Etching Technique ◽  
Parametric Relationship ◽  
Machined Parts ◽  
Instability Parameter ◽  
Stress Profiles

The production of precision parts requires manufacturing processes which produce low residual stresses. This study was designed to investigate the parametric relationship between machining processes and residual stress distribution. Sets of steel specimens were single point turned at different feeds. The residual stress profiles of these specimens were monitored, using a continuous etching technique. A “Specific Instability Potential” parameter, derived from the strain energy of the residual stresses, was found to relate directly to the machining parameters. It is suggested that the Specific Instability Potential can be used as a parameter for specifying processing operations.

Finite element modeling of residual stress profile patterns in hard turning

2009 ◽  
Vol 24 (S1) ◽  
pp. S22-S25
Author(s):  
Y. B. Guo ◽  
S. Anurag
Keyword(s):  
Residual Stress ◽  
Finite Element ◽  
Finite Element Modeling ◽  
Hard Turning ◽  
Internal State ◽  
Stress Profile ◽  
Surface Residual Stress ◽  
Mechanical Coupling ◽  
Element Modeling ◽  
Stress Profiles

Hard turning, i.e., turning hardened steels, may produce the unique “hook” shaped residual stress (RS) profile characterized by surface compressive RS and subsurface maximum compressive RS. However, the formation mechanism of the unique RS profile is not yet known. In this study, a novel hybrid finite element modeling approach based on thermal-mechanical coupling and internal state variable plasticity model has been developed to predict the unique RS profile patterns by hard turning AISI 52100 steel (62 HRc). The most important controlling factor for the unique characteristics of residual stress profiles has been identified. The transition of maximum residual stress at the surface to the subsurface has been recovered by controlling the plowed depth. The predicted characteristics of residual stress profiles favorably agree with the measured ones. In addition, friction coefficient only affects the magnitude of surface residual stress but not the basic shape of residual stress profiles.

scholarly journals Residual Stress State of X65 Pipeline Girth Welds Before and After Local and Furnace Post Weld Heat Treatment

2017 ◽  
Vol 139 (4) ◽  
Author(s):  
Yao Ren ◽  
Anna Paradowska ◽  
Bin Wang ◽  
Elvin Eren ◽  
Yin Jin Janin
Keyword(s):  
Heat Treatment ◽  
Residual Stress ◽  
Residual Stresses ◽  
Outer Surface ◽  
Post Weld Heat Treatment ◽  
Pipe Length ◽  
Stress Profiles ◽  
Girth Welds ◽  
Welded Pipe ◽  
Weld Heat

This research investigated the effects of global (in other words, furnace-based) and local post weld heat treatment (PWHT) on residual stress (RS) relaxation in API 5L X65 pipe girth welds. All pipe spools were fabricated using identical pipeline production procedures for manufacturing multipass narrow gap welds. Nondestructive neutron diffraction (ND) strain scanning was carried out on girth welded pipe spools and strain-free comb samples for the determination of the lattice spacing. All residual stress measurements were carried out at the KOWARI strain scanning instrument at the Australian Nuclear Science and Technology Organization (ANSTO). Residual stresses were measured on two pipe spools in as-welded condition and two pipe spools after local and furnace PWHT. Measurements were conducted through the thickness in the weld material and adjacent parent metal starting from the weld toes. Besides, three line-scans along pipe length were made 3 mm below outer surface, at pipe wall midthickness, and 3 mm above the inner surface. PWHT was carried out for stress relief; one pipe was conventionally heat treated entirely in an enclosed furnace, and the other was locally heated by a flexible ceramic heating pad. Residual stresses measured after PWHT were at exactly the same locations as those in as-welded condition. Residual stress states of the pipe spools in as-welded condition and after PWHT were compared, and the results were presented in full stress maps. Additionally, through-thickness residual stress profiles and the results of one line scan (3 mm below outer surface) were compared with the respective residual stress profiles advised in British Standard BS 7910 “Guide to methods for assessing the acceptability of flaws in metallic structures” and the UK nuclear industry's R6 procedure. The residual stress profiles in as-welded condition were similar. With the given parameters, local PWHT has effectively reduced residual stresses in the pipe spool to such a level that it prompted the thought that local PWHT can be considered a substitute for global PWHT.

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