Comparative study of heat-affected zone with weld and base material after post-weld heat treatment of HSLA steel using ball indentation technique

2008 ◽  
Vol 43 (16) ◽  
pp. 5474-5482 ◽  
Author(s):  
Sabita Ghosh ◽  
T. K. Pal ◽  
Surojit Mukherjee ◽  
Goutam Das ◽  
Sukomal Ghosh
Keyword(s):  
Heat Treatment ◽  
Comparative Study ◽  
Heat Affected Zone ◽  
Hsla Steel ◽  
Base Material ◽  
Post Weld Heat Treatment ◽  
Indentation Technique ◽  
Ball Indentation ◽  
Weld Heat

Weld Hardness Study of P91 Welded Pipes with Post Weld Heat Treatment for Elevated Temperature Application in Power Plants

2015 ◽  
Vol 1115 ◽  
pp. 503-508 ◽  
Author(s):  
Muhammad Sarwar ◽  
Mohd Amin bin Abd Majid
Keyword(s):  
Heat Treatment ◽  
Power Plant ◽  
Weld Metal ◽  
Creep Strength ◽  
Power Plants ◽  
Thermal Power ◽  
Base Material ◽  
Welding Process ◽  
Post Weld Heat Treatment ◽  
Weld Heat

The creep strength-enhanced ferritic (CSEF) steels are undergoing an encouraged use around the world especially in power plant construction. On construction sites, it has always been the target to have no problems in welded joints but premature failures are being encountered. The primary reason of these premature failures is found to be the improper heat treatment that is mandatorily carried out to achieve the required weld hardness. Weld hardness has close relationship with creep strength and ductility of the welded structures. Hence it is important for any weld to achieve certain level of weld hardness. This study aims at ascertaining the importance of Post Welding Heat Treatment (PWHT) in achieving the required hardness in creep-strength enhanced ferritic (CSEF) materials.The study was carried out on the welding of alloy steel ASTM A335 Gr. P-91 with the same base material (ASTM A335 Gr. P-91) by Gas Tungsten Arc Welding (GTAW) process using ER90S-B9 filler wire with pre-heat of 200oC (min) and inter-pass temperature of 300oC (max). After welding, the joints were tested for soundness with Radiography testing. Induction heating was used for heat treatment of P91 pipes during welding and post weld heat treatment. The effect of Post Weld Heat Treatment (PWHT) was investigated on the Weld metal and the Heat Affected Zones (HAZ) by hardness testing. It is perceived that the scattered and higher hardness values, more than 250HB in 2” P91 pipes in the weld metal and in the heat affected zones, can be brought into the lower required level, less than 250HB, with an effective post weld heat treatment at 760°C for 2hrs.It is concluded that PWHT is the most effective way of relieving the welding stresses that are produced due to high heat input in the welding process and to achieve the required level of hardness in the weld as well as in the heat affected zones (HAZ) in thermal power plant main steam piping.

Fatigue of Laserbeam Welded Joints of High-Carbon Steel Strips

2010 ◽  
Vol 659 ◽  
pp. 61-66
Author(s):  
Attila Magasdi ◽  
János Ginsztler ◽  
János Dobránszky
Keyword(s):  
Mechanical Properties ◽  
Heat Treatment ◽  
Carbon Steel ◽  
Heat Affected Zone ◽  
Welded Joints ◽  
High Carbon Steel ◽  
Post Weld Heat Treatment ◽  
High Carbon ◽  
Steel Strips ◽  
Weld Heat

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.

Friction Stir Welding of Al-Li AA2199: Parameters, Precipitates and Post Weld Heat Treatment

2011 ◽  
Vol 409 ◽  
pp. 853-858
Author(s):  
Rosen Ivanov ◽  
Julien Boselli ◽  
Diana Denzer ◽  
Daniel Larouche ◽  
Raynald Gauvin ◽  
...  
Keyword(s):  
Heat Treatment ◽  
High Temperature ◽  
Friction Stir Welding ◽  
Weld Zone ◽  
Base Material ◽  
Post Weld Heat Treatment ◽  
Second Phase ◽  
Friction Stir ◽  
Tool Rotation ◽  
Weld Heat

The aerospace industry strives to develop materials allowing an increase in payload and reducing fuel consumption. Al-Li alloys, with their low density and high strength are currently in use for such applications and have potential for additional applications. When compared to composites, utilizing Al-Li alloy products is cost effective for aerospace companies as they do not need to redesign pre-existing fabrication facilities. The joining of these alloys by conventional methods is limited by segregation of alloying elements and the formation of oxides during high temperature exposure. This study focuses on solid state joining method that has the potential to generate low heat and be defect free - Friction Stir Welding (FSW). AA2199 sheets were joined by FSW. Process variables included table force, tool rotation speed and weld travel speed. A post weld heat treatment (PWHT) was applied to improve the mechanical properties by precipitation of strengthening phases. An increase in hardness of the weld zone from 95HV to 125HV upon PWHT was recorded for selected welding conditions. The type and morphology of second phase precipitates is deemed responsible for this effect. It is suggested that the high temperature and high strain levels characteristic of welds with fast tool rotation allow for the dissolution of precipitates during welding. The re-precipitation of these second phases during PWHT allowed the welds to recover strength to the level of the base material.

Effect of Post-Weld Heat Treatment on Carbide Precipitation and Impact Properties of Coarse-Grained Heat-Affected Zone of Q690 Steel

2014 ◽  
Vol 989-994 ◽  
pp. 576-580 ◽  
Author(s):  
Zhen Shun Li ◽  
Sheng Li Li ◽  
Lei Tian ◽  
Xiang Hai Zhang ◽  
Ji Zhi Liu
Keyword(s):  
Heat Treatment ◽  
Grain Boundaries ◽  
Heat Affected Zone ◽  
Unit Area ◽  
Carbide Precipitation ◽  
Post Weld Heat Treatment ◽  
Coarse Grained ◽  
Impact Properties ◽  
Carbide Particles ◽  
Weld Heat

The effect of post-weld heat treatment (PWHT) on carbide precipitation and impact properties of coarse-grained heat-affected zone (CGHAZ) of Q690 Steel was studied in this paper. Carbide particles precipitated primarily at prior austenite grain boundaries and martensitic lath boundaries. When the PWHT temperature is 520–570 °C, temper embrittlement occurs. This temperature range is also where the number of carbide particles per unit area at grain boundaries reaches its maximum. The high number of particles per unit area increases the rate of crack initiation at grain boundaries under rapid loading; linking of microcracks along grain boundaries which are already weakened by impurity segregation results in TE and intergranular fracture.

Sign in / Sign up

Export Citation Format

Share Document