Friday, November 20, 2009

Mechanical property variation within Inconel 82/182 dissimilar metal weld between low alloy steel and 316 stainless steel

Abstract

In several locations of pressurized water reactors, dissimilar metal welds using Inconel welding wires are used to join the low alloy steel components to stainless-steel pipes. Because of the existence of different materials and chemistry variation within welds, mechanical properties, such as tensile and fracture properties, are expected to show spatial variation. For design and integrity assessment of the dissimilar welds, these variations should be evaluated.
In this study, dissimilar metal welds composed of low alloy steel, Inconel 82/182 weld, and stainless steel were prepared by gas tungsten arc welding and shielded metal arc welding techniques. Microstructures were observed using optical and electron microscopes. Typical dendrite structures were observed in Inconel 82/182 welds.
Tensile tests using standard and mini-sized specimens and micro-hardness tests were conducted to measure the variation in strength along the thickness of the weld as well as across the weld. In addition, fracture toughness specimens were taken at the bottom, middle, and top of the welds and tested to evaluate the spatial variation along the thickness. It was found that while the strength is about 50–70MPa greater at the bottom of the weld than at the top of the weld, fracture toughness values at the top of the weld are about 70% greater than those at the bottom of the weld.

Tuesday, November 17, 2009

Preparation procedure of the 316l h3 & h4 weld mock-up

Recent studies suggest that material hardening should cause enhancement in stress corrosion cracking (SCC) growth rate of stainless steels (SS).

BWR plants, stress corrosion cracking (SCC) in components such as the reactor core shroud and primary loop re-circulation (PLR) piping made of Lgrade stainless steel (SS) has been an issue since 2003.

Investigation on SCC in the core shroud has revealed the following,
  1. Nearly 3601 circumferential discrete cracks existed in the ring along the weld between the shroud shell and the ring. Most of the cracks were several mm away from the fusion line.
  2. Several radial cracks were found in the heat-affected zone (HAZ) of H4 weld, the highest fluence position in the shroud, some of which propagated into the weld metal
Recently, it is concerned that the SS of high yield strength or hardness tends to provide high SCC growth rate. The da/dt-K diagrams that were prepared based on L-grade SS (heat treatment with 620 1C_24 h) SCC data might not envelope the condition of radiation-hardened and/or cold worked shroud. Incidentally, in the process of investigating PLR piping SCC, the hardness of weld HAZ was found to be around 250 HV and many SCC growth data with the PLR piping weld joint mock-ups were acquired to prepare a new diagram for hardened SS [3].

Since the reactor core shroud suffers from neutron irradiation, it would provide different SCC behaviors. Main factors for increasing crack growth rates seem to be the increased yield strength due to the cyclic weld heat input and the neutron irradiation effect.

Fig. 1. Reactor core shroud:


Fig. 2. Preparation procedure of the 316L H3 weld mock-up:

Fig. 3. Geometry of 0.5T-CT specimen made from the shroud mockups (Dimensions are in mm):


Fig. 4 Geometry of 1T-CT specimen made from the actually used shroud:



Fig. 5. Result of micro-vickers hardness measurement (H3):



Fig. 6. Result of micro-vickers hardness measurement (H4):



See this Experimental procedure at the following url,
http://www.4shared.com/file/153740839/ef18c0d/SCC_growth_behavior_of_BWR_core_shroud_materials.html

Monday, November 16, 2009

AutoCAD-2010 Tips and tricks

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The latest version of AutoCAD-2010 software introduces groundbreaking new capabilities to help users meet their toughest design problems, including free-form design tools, parametric design and enhanced PDF support, begging the question of International Group Users of Autodesk (AUGI) members.

Additionally it offers even more power and innovation to help users document, communicate, customize and explore design ideas.

With the new free-form design tools, users can more easily explore ideas into 3D models to create almost any shape imaginable.

New PDF Import and running and growing base of features can improve two-way communication with the expansion of the design team.

Moreover, the introduction of constraints based on parametric drawing tools allows users to define the persistence of relationships between objects, accelerating workflows critical design review.

AutoCAD 2010 also now supports 3D printing, which makes it easy to produce 3D physical models and physical prototypes by connecting to demand 3D printing services or personal 3D printers.

Autocad2010 trial version for students
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Download Autocad2010 full version with crack (english)
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System Requirements
Description Requirements

32bit Operating System: Windows Vista Enterprise, Business, Ultimate, Home Premium (SP1), Windows XP Professional, Home Edition (SP2 or higher) 64bit: Windows Vista  Enterprise, Business, Ultimate, Home Premium (SP1), Windows  XP Professional x64 Edition (SP2 or higher)

Browser Windows Internet Explorer 7.0 or higher

32bit CPU: Windows Vista: Intel Pentium  4 or AMD Athlon Dual Core, 3.0 GHz or higher with technology SSE2Windows XP: Intel Pentium 4 or AMD Athlon Dual Core, 1.6 GHz or higher with SSE2 technology

  • 64bit: AMD Athlon ® 64 or Opteron ® with SSE2 technology
  • Intel ® Pentium ® 4 or Xeon ® processor with Intel EM64T with SSE2 technology
  • Windows Vista RAM: 2 GB RAM
  • Windows XP: 2 GB RAM
  • Monitor 1024 x 768 with true color
  • Hard Disk Space 32bit: 1 GB free for installation
  • 64bit: 1.5 GB free space for installation
  • MS-Mouse pointing device compatible
  • Media (CD ROM vs. DVD) Download or Installation from DVD or CD-ROM
  • Additional Requirements 3D Intel Pentium 4 or AMD Athlon, 3.0 GHz or higher;
  • Intel or AMD Dual Core, 2.0 GHz or higher
  • 2 GB RAM or higher
  • 2 GB of free space apart from the installation
  • 1280 x 1024 32-bit video display adapter, color (true color) 128 MB or higher, Direct3D capable

Saturday, November 14, 2009

Why this blog has started?

It is really hard to track all kind of tools, articles, e-books, free and cracked versions of niche softwares, which are useful to students and professionals in the field of mechanical and petrochemical industry.

So we planned to start this blog, where we will post anything which are related to the mechanical industry, whenever available or known to us. We also encourage and welcome our viewers to post niche articles, pdf's, e-books, software links in the comments, that helps us to review and publish through the upcoming posts.

Thanks to all our community members and supporters!
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