Effect of stress raisers on the strength of welded joints in a martensitic steel

1988 ◽  
Vol 2 (9) ◽  
pp. 774-775
Author(s):  
A I Pustovit ◽  
S A Voronin ◽  
K A Yushchenko
Keyword(s):  
Welded Joints ◽  
Martensitic Steel ◽  
Stress Raisers

scholarly journals Microstructure and Mechanical Properties of Modern 11%Cr Heat-Resistant Steel Weld Joints

Materials ◽  
2021 ◽  
Vol 14 (12) ◽  
pp. 3430
Author(s):  
Grzegorz Golański ◽  
Jacek Słania ◽  
Marek Sroka ◽  
Paweł Wieczorek ◽  
Michał Urzynicok ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Welded Joints ◽  
Martensitic Steel ◽  
Base Material ◽  
Hardness Measurement ◽  
Power Industry ◽  
Strength Properties ◽  
Typical Structure ◽  
Δ Ferrite ◽  
The Impact

In addition to good high-temperature creep resistance and adequate heat resistance, steels for the power industry must have, among other things, good weldability. Weldability of such steels is one of the criteria determining whether or not the material is suitable for applications in the power industry. Therefore, when materials such as martensitic steel Thor 115 (T115) are introduced into the modern power industry, the quality and properties of welded joints must be assessed. The paper presents the results of metallographic and mechanical investigations of T115 martensitic steel welded joints. The analysis was carried out on joints welded with two filler metals: WCrMo91 (No. 1) and EPRI P87 (No. 2). The scope of the investigations included: microstructural investigations carried out using optical, scanning and transmission electron microscopy and mechanical testing, i.e., Vickers microhardness and hardness measurement, static tensile test and impact test. The macro- and microstructural investigations revealed correct structure of the weld, without welding imperfections. The microstructural investigations of joint No. 1 revealed a typical structure of this type of joint, i.e., the martensitic structure with numerous precipitates, while in joint No. 2, the so-called Nernst’s layers and δ-ferrite patches were observed in the weld fusion zone as well as the heat affected zone (HAZ). The mechanical properties of the test joints met the requirements for the base material. A slight influence of the δ-ferrite patch on the strength properties of joint No. 2 was observed, and its negative effect on the impact energy of HAZ was visible.

scholarly journals Properties and Microstructure of Laser Welded VM12-SHC Steel Pipes Joints

2016 ◽  
Vol 61 (2) ◽  
pp. 1143-1149 ◽  
Author(s):  
A. Skrzypczyk ◽  
H. Danielewski
Keyword(s):  
High Power ◽  
Vickers Hardness ◽  
Welded Joints ◽  
Martensitic Steel ◽  
Steel Pipes ◽  
Hardness Tests ◽  
Steam Boilers ◽  
Welding Head ◽  
New Generation ◽  
Non Destructive

Abstract Paper presents results of microstructure and tests of welded joints of new generation VM12-SHC martensitic steel using high power CO2 laser (LBW method) with bifocal welding head. VM12-SHC is dedicated to energetic installation material, designed to replace currently used. High content of chromium and others alloying elements improve its resistance and strength characteristic. Use of VM12-SHC steel for production of the superheaters, heating chambers and walls in steam boilers resulted in various weldability researches. In article are presented results of destructive and non-destructive tests. For destructive: static bending and Vickers hardness tests, and for non-destructive: VT, RT, UT, micro and macroscopic tests were performed.

Characteristics of Fusion-Welded Joints Made Using Martensitic Steel after 100,000 Hours in Service

2016 ◽  
Vol 246 ◽  
pp. 177-182
Author(s):  
Adam Hernas ◽  
Adrian Mościcki ◽  
Roman Krupa
Keyword(s):  
Welded Joints ◽  
Martensitic Steel ◽  
Welding Process ◽  
Fusion Welding ◽  
Tube Material ◽  
Butt Joints ◽  
National Centre ◽  
Fusion Welded Joints

The paper presents the results of tests of mixed fusion-welded joints consisting of superheater pipes of grades T91 and HCM12A(T122) after 100,000 hours in service in a BB-1150 boiler welded to new pipes (in “as-delivered” condition) of grades T91 and VM12-SHC. The state of the microstructure and properties of the used tube material after long term service are characterized. The paper describes fusion welding conditions and parameters, and evaluates the quality of the created butt joints. The results of tests of the macro-and microstructure of the joints and their mechanical properties are presented. It was determined that the welding process intensifies further degradation of the tested materials to a small extent only. This work was performed under the Strategic Research Project No SP/E/1/67484/10 supported by the National Centre for Research and Development.

Laser Beam Welding for Reduced Activation Ferritic/Martensitic Steel F82H

2014 ◽  
Vol 783-786 ◽  
pp. 2771-2776 ◽  
Author(s):  
Hiroaki Mori ◽  
Hiroyuki Ogiwara ◽  
Kazuyoshi Saida ◽  
Hisashi Serizawa ◽  
Takanori Hirose ◽  
...  
Keyword(s):  
Heat Treatment ◽  
Laser Beam ◽  
Base Metal ◽  
Cross Sections ◽  
Welded Joints ◽  
Martensitic Steel ◽  
Laser Beam Welding ◽  
Charpy Impact ◽  
Charpy Impact Test ◽  
Power Sources

A fusion reactor is expected as one of the new electric power sources in next generation. Reduced activation ferritic/martensitic steel F82H is planned to be used as a structural material for the blanket modules set on the inner wall of the reactor. However, especially in the case of laser beam welding (LBW), the weldability of the steel was not completely clarified. On the other hand, although post weld heat treatment (PWHT) should be conducted for the welds of the steel in accordance with general standards for chrome steels, the heat treatment conditions were uncertain. Therefore, adaptability of LBW as a joining method for the steel and the applicable PWHT conditions for the welded joints were investigated in this study. The effect of LBW conditions on weld penetration behavior were ascertained by observation of cross sections in the welds. The adequate PWHT conditions were confirmed in consideration of both hardness distributions measured in welds and ductile-brittle transition temperatures (DBTT) evaluated using Charpy impact test. Full penetration without weld defects such as hot cracking, porosity etc. was obtained for plates with the thickness of 4mm of the steel by control welding conditions. That means laser beam is one of useful welding heat sources to realize sound weld joints of the steel. In addition, due to select appropriate PWHT conditions, the hardness in welds was suppressed to the level of base metal and the toughness in the welded joints was improved to a practical level without the damage to base metal.

scholarly journals Effect of Postweld Heat Treatments on Type IV Creep Failure in the Intercritical Heat-Affected Zone of 10% Cr Martensitic Steel Welded with Haynes 282 Filler

Metals ◽  
2021 ◽  
Vol 11 (5) ◽  
pp. 726
Author(s):  
Namkyu Kim ◽  
Yongjoon Kang ◽  
Jinhyeok Bang ◽  
Sangwoo Song ◽  
Seong-Moon Seo ◽  
...  
Keyword(s):  
Heat Affected Zone ◽  
Welded Joints ◽  
Martensitic Steel ◽  
Laves Phase ◽  
Lower Amount ◽  
Failure Behavior ◽  
Creep Life ◽  
Creep Failure ◽  
Type Iv ◽  
Postweld Heat

This study investigated the effect of postweld heat treatment (PWHT) conditions on Type IV failure behavior of 10% Cr martensitic steel welds using Haynes 282 filler. The welded joints were subjected to PWHT at temperatures of 688, 738, and 788 °C for 4 and 8 h. Creep tests were carried out at 600 °C under a stress of 200 MPa. The as-welded joint without PWHT showed Type IV cracking due to growth of voids around Laves phase by localized creep deformation in the intercritical heat-affected zone (ICHAZ). The creep properties of the PWHTed joints at 688 °C were similar to those of the as-welded joints without PWHT. On the other hand, the PWHTed joints at 738 °C exhibited a significantly longer creep life by a lower amount of Laves phase in the ICHAZ than those at 688 °C; this could be a result of the homogenization of ICHAZ microstructure during PWHT at 738 °C. However, the PWHT at 688 and 738 °C showed the same Type IV creep failure mode. Meanwhile, the PWHTed joints at 788 °C exhibited the shortest creep life in this study. The failure location was shifted to the base metal away from the HAZ, and severe plastic deformation occurred due to the softened matrix by excessive tempering.

Testing of Welded Joints of Gas-Tight Pipe Walls Made of New Generation Martensitic Steel Type VM12-SHC

2016 ◽  
Vol 246 ◽  
pp. 71-74
Author(s):  
Stanisław Lalik ◽  
Jarosław Adamski ◽  
Andrzej Balcerzyk
Keyword(s):  
Corrosion Resistance ◽  
Welded Joints ◽  
Martensitic Steel ◽  
High Corrosion Resistance ◽  
Steel Pipes ◽  
Heat Treated ◽  
Welding Procedure ◽  
New Generation ◽  
Gas Tight ◽  
Submerged Arc

The paper presents the results of macro and microstructure testing and of hardness measurements of submerged arc welded joints of VM12SHC steel pipes (special high corrosion resistance, X12CrCoWVNbN12-2-2) with flat bars made of 10CrMo910 steel, intended for operation in elevated temperature. The tests were performed on welded joints that were not heat-treated and welded joints that were annealed (at 735-745°C for 0.5 hours) after welding. The results of the tests were used as a base to elaborate a Welding Procedure Specification.

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