Phase transformations and numerical modelling in simulated HAZ of nanostructured P91B steel for high temperature applications

被引：139

作者：

Akhtar, Modassir ^{[1
]}

Khajuria, Akhil ^{[2
]}

Sahu, Jitendra K. ^{[3
]}

Swaminathan, J. ^{[3
]}

Kumar, Rajneesh ^{[4
]}

Bedi, Raman ^{[2
]}

Albert, Shaju K. ^{[5
]}

机构：

[1] Natl Inst Technol, Dept Met & Mat Engn, Warangal 506004, Andhra Pradesh, India

[2] Natl Inst Technol, Dept Mech Engn, Jalandhar 144011, India

[3] CSIR Natl Met Lab, Mat Engn Div, Jamshedpur 831007, Bihar, India

[4] CSIR Natl Met Lab, Project Planning & Engn Div, Jamshedpur 831007, Bihar, India

[5] Indira Gandhi Ctr Atom Res, Mat Technol Div, Kalpakkam 603102, Tamil Nadu, India

来源：

APPLIED NANOSCIENCE | 2018年 / 8卷 / 07期

关键词：

P91B steel; Simulated sub-HAZ; Phase transformation; Effect of boron; Apparent activation energy; AUSTENITE GRAIN-GROWTH; MICROSTRUCTURE EVOLUTION; CREEP STRENGTH; HEAT-TREATMENT; IV FRACTURE; WELD JOINTS; CRACKING; BORON; ZONE; SUPPRESSION;

D O I：

10.1007/s13204-018-0854-1

中图分类号：

TB3 [工程材料学];

学科分类号：

0805 ; 080502 ;

摘要：

This paper critically assesses phase transformations occurring after welding and subsequent post weld heat treatments in simulated sub-heat affected zones (HAZ) of P91B steel. Samples for weld-HAZ simulation were produced corresponding to grain-coarsened HAZ, grain-refined HAZ and inter-critical HAZ. Analyses revealed diverse phase transformation mechanisms (for GCHAZ =pipe-diffusion and for GR/ICHAZ = GB-diffusion) owing to manipulation in grain size and boron-enriched nanosized particles as regards virgin steel after welding. However, after PWHT, same phase transformation mechanism (interface diffusion) in all simulated sub-HAZs is observed. Hardness evaluations and prior austenite grain boundaries dissolution confirm GB embrittlement after welding. Boron segregation, the presence of borides and boron-enriched particles heads to similar to 50% drop in hardness deviations enhancing GB hardening after PWHT. Particle refinement is observed after PWHT which is further validated by numerical modelling. In addition, particle evolution during cooling from peak temperature of weld thermal cycle and isothermal holding of PWHT is analysed. Apparent activation energy of nucleation/growth follows descending order, i.e. GC/GR/ICHAZ for nanosized particles during welding.

引用

页码：1669 / 1685

页数：17

共 42 条

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