Development of the matching filler metal for MARBN—new advanced creep resisting alloys for thermal power plant

Zhang, Zhuyao; Mee, V. van der

doi:10.1007/s40194-021-01104-4

Cited by 2 publications

(2 citation statements)

References 7 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Further increasing holding time to 16 hours and 36 hours did not produce further considerable changes in properties, but did see certain degree of reduction in tensile strength and hardness. The toughness values achieved after PWHT 735°C with holding time above 8 hours are very similar to those reported after PWHT 765°C for 2 and 4 hours with standard AWS A5.5 all-weld metal classi cation assembly [11] .…”

Section: Filler Metalsupporting

confidence: 83%

See 1 more Smart Citation

Welding procedure development and effect of PWHT on the microstructure and properties of the matching filler metal and weld joint of the MARBN alloy

Roberts,

Wildgoose,

Jepson

et al. 2023

Preprint

Self Cite

View full text Add to dashboard Cite

Since the reports of promising creep properties of MARBN alloys (a short name for MARtensitic 9Cr steel strengthened by Boron and Nitrides), nearly two decades ago, significant effort has been input in examining the base alloys, development and validating of the matching filler metals. One of the main targeted applications of MARBN alloys is the castings for thermal power plant turbine components. These applications will involve repair welding of castings and joint welding between castings and other structures, such as joints between casted valves and steam pipe works, etc. For weld joints with satisfactory microstructure and properties, there are practical needs for developing appropriate welding procedures and post weld heat treatment (PWHT) parameters. Particularly, a relatively lower PWHT peak temperature, i.e. 735°C, is preferred for the fabrication of casting components. Within the UK collaborative projects, IMPLANT, a detailed investigation has been carried out to the matching composition filler metal for welding MARBN alloys to explore the influence of welding procedure and PWHT on the microstructure and properties of the weld metal and MARBN alloy weld joint. The filler metal was in form of shielded metal arc welding (SMAW) electrode. All-weld metal assemblies and weld joints made with IBN-1 base alloy plate were prepared. For the weld joint welding, different inter-pass temperatures were applied. After welding, post weld heat treatments at 735°C with different soaking durations were employed. Ambient temperature mechanical test was conducted. All-weld metal and cross-weld transverse tensile, Charpy impact toughness, hardness and bend properties were assessed. The microstructure of the all-weld metals and weld joint after different PWHT procedures were examined using optical microscopy and scanning electron microscopy (SEM). The differences in microstructure (grain structure and precipitations, etc) are evaluated in order to determine the possible reasons for the differences in mechanical properties, particularly in toughness at ambient temperature. This paper reports the results obtained so far. Initial conclusions are summarised. Aspects for further investigation are identified.

show abstract

Section: Filler Metalsupporting

confidence: 83%

“…Since the reports of promising creep properties of MARBN alloys (a short name for MARtensitic 9Cr steel strengthened by Boron and Nitrides), nearly two decades ago [1][2][3] , signi cant effort has been input in validating the base alloys, development of the matching ller metals [4][5][6][7][8][9][10][11][12] .…”

Section: Introductionmentioning

confidence: 99%

Welding procedure development and effect of PWHT on the microstructure and properties of the matching filler metal and weld joint of the MARBN alloy

Roberts,

Wildgoose,

Jepson

et al. 2023

Preprint

Self Cite

View full text Add to dashboard Cite

show abstract

Effects of post-weld heat treatment on the microstructure and properties of the matching SMAW filler metal for weld joints in MarBN steel

Zhang,

Roberts,

Wildgoose

et al. 2024

Weld World

View full text Add to dashboard Cite

A detailed investigation has been carried out of the matching composition filler metal for welding MarBN steel to explore the influence of welding procedure and post-weld heat treatment (PWHT) on the microstructure and properties of the weld metal and a MarBN steel weld joint. The filler metal was in the form of a shielded metal arc welding (SMAW) electrode. With different interpass temperatures and PWHT procedures applied, the microstructure and mechanical properties, particularly toughness, of the all-weld metal deposits and welded MarBN alloy joints were examined. The differences in microstructure (grain structure, precipitates, etc.) were evaluated to provide a better understanding of how the PWHTs influence the starting conditions of the matching weld metal and welded MarBN steel joints before service. The current work found that for a 30-mm-thick all-weld metal coupon, reasonable impact toughness was achieved after PWHT of 735 °C × 8 h; longer heat treatment durations (16 h and 36 h) did not further increase the toughness. For thicker cast blocks, a PWHT of 735 °C × 16 h was needed for weld toughness comparable to the base metal, hence was considered more appropriate for actual engineering applications. Evenly distributed Laves phase precipitation was observed after 735 °C × 8 h; the precipitates gradually increased in size and area fraction as the duration increased, and appeared to be stable when approaching 36 h. Differences in the precipitation were observed between different weld regions. The weld cap region had a lower density of Laves precipitates compared to the lower weld area. From the current investigation, aspects for further investigation are also identified.

show abstract

Development of the matching filler metal for MARBN—new advanced creep resisting alloys for thermal power plant

Cited by 2 publications

References 7 publications

Welding procedure development and effect of PWHT on the microstructure and properties of the matching filler metal and weld joint of the MARBN alloy

Welding procedure development and effect of PWHT on the microstructure and properties of the matching filler metal and weld joint of the MARBN alloy

Effects of post-weld heat treatment on the microstructure and properties of the matching SMAW filler metal for weld joints in MarBN steel

Contact Info

Product

Resources

About