Effects of in-situ post-weld heat treatment on the microstructure and mechanical properties of the coarse-grained heat-affected zone in a resistance spot weld in medium Mn TRIP steel

2020 ◽  
Vol 788 ◽  
pp. 139477 ◽  
Author(s):  
Gitae Park ◽  
Sangho Uhm ◽  
Changhee Lee
2011 ◽  
Vol 214 ◽  
pp. 108-112 ◽  
Author(s):  
Prachya Peasura ◽  
Bovornchok Poopat

The Inconel X-750 indicates good hot corrosion resistance, high stability and strength at high temperatures and for this reason the alloy is used in manufacturing of gas turbine hot components. The objective of this research was study the effect of post weld heat treatment (PWHT) on fusion zone and heat affected zone microstructure and mechanical properties of Inconel X-750 weld. After welding, samples were solutionized at 1500 0C. Various aging temperature and times were studied. The results show that aging temperature and time during PWHT can greatly affect microstructure and hardness in fusion zone and heat affected zone. As high aging temperature was used, the grain size also increased and M23C6 at the grain boundary decreased. This can result in decreased of hardness. Moreover excessive aging temperature can result in increasing MC carbide intensity in parent phase (austenite). It can also be observed that M23C6 at the grain boundary decreased due to high aging temperature. This resulted in decreasing of hardness of weld metal and heat affected zone. Experimental results showed that the aging temperature 705 0C aging time of 24 hours provided smaller grain size, suitable size and intensity of MC carbide resulting in higher hardness both in weld metal and HAZ.


2010 ◽  
Vol 659 ◽  
pp. 61-66
Author(s):  
Attila Magasdi ◽  
János Ginsztler ◽  
János Dobránszky

The high-carbon steel strips are one of the most widely used base materials of bandsaw blade manufacturing. These materials have sufficient strength and ductility to cope with the high fatigue load of the bandsaw blades. These endless strips are produced by welding, and therefore the weld and the heat affected zone have different mechanical properties, like tensile strength and fatigue resistance, than the base material. These properties of the weld can be influenced by preheat and post weld heat treatment. Regarding to the latest industrial requirements, the application of laserbeam welding was examined to produce higher standard bandsaw blade. The laserbeam welded joints has lower heat input and narrower heat affected zone compared to metal inert gas (MIG) welding, which is currently used in bandsaw blade manufacturing. To assure the proper mechanical properties and sufficient resistance to fatigue, an examination was carried out to determine the effect of preheat temperature and post weld heat treatment time on the mechanical properties and fatigue behaviour of the laserbeam welded joint.


2006 ◽  
Vol 15-17 ◽  
pp. 1014-1019 ◽  
Author(s):  
Peter Mayr ◽  
T.A. Palmer ◽  
J.W. Elmer ◽  
Horst Cerjak

A basic requirement for the production of large power plant components from ferritic/martensitic 9-12% Cr steels is good weldability. Weldments in these steels are often reported as the weak spots. In this work the weldability of a creep resistant 9% Cr steel is discussed. Different methods are utilized to characterize the microstructural evolution during different welding cycles and the following post weld heat treatment, as well as the resulting mechanical properties. Heat affected zone (HAZ) simulation using a thermo-mechanical testing device GLEEBLE 1500 is performed to study the microstructural evolution and changes in the mechanical properties in the different parts of the HAZ. Specimens exposed to peak temperatures higher than 1150°C showed a minimum of impact toughness after post weld heat treatment (PWHT). In situ X-ray diffraction experiments with synchrotron radiation are used to observe phase transformations during heating to elevated temperatures, where delta ferrite formation was observed at temperatures higher than 1250°C.


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