共查询到20条相似文献,搜索用时 31 毫秒
1.
K. Laha K. S. Chandravathi K. Bhanu Sankara Rao S. L. Mannan D. H. Sastry 《Metallurgical and Materials Transactions A》2001,32(1):115-124
The evaluation of the creep deformation and fracture behavior of a 2.25Cr-1Mo steel base metal, a 2.25Cr-1Mo/2.25Cr-1Mo similar
weld joint, and a 2.25Cr-1Mo/Alloy 800 dissimilar weld joint at 823 K over a stress range of 90 to 250 MPa has been carried
out. The specimens for creep testing were taken from single-V weld pads fabricated by a shielded metal arc-welding process
using 2.25Cr-1Mo steel (for similar-joint) and INCONEL 182 (for dissimilar-joint) electrodes. The weld pads were subsequently
given a postweld heat treatment (PWHT) of 973 K for 1 hour. The microstructure and microhardness of the weld joints were evaluated
in the as-welded, postweld heat-treated, and creep-tested conditions. The heat-affected zone (HAZ) of similar weld joint consisted
of bainite in the coarse-prior-austenitic-grain (CPAG) region near the fusion line, followed by bainite in the fine-prior-austenitic-grain
(FPAG) and intercritical regions merging with the unaffected base metal. In addition to the HAZ structures in the 2.25Cr-1Mo
steel, the dissimilar weld joint displayed a definite INCONEL/2.25Cr-1Mo weld interface structure present either as a sharp
line or as a diffuse region. A hardness trough was observed in the intercritical region of the HAZ in both weld joints, while
a maxima in hardness was seen at the weld interface of the dissimilar weld joint. Both weld joints exhibited significantly
lower rupture lives compared to the 2.25Cr-1Mo base metal. The dissimilar weld joint exhibited poor rupture life compared
to the similar weld joint, at applied stresses lower than 130 MPa. In both weld joints, the strain distribution across the
specimen gage length during creep testing varied significantly. During creep testing, localization of deformation occurred
in the intercritical HAZ. In the similar weld joint, at all stress levels investigated, and in the dissimilar weld joint,
at stresses ≥150 MPa, the creep failure occurred in the intercritical HAZ. The fracture occurred by transgranular mode with
a large number of dimples. At stresses below 150 MPa, the failure in the dissimilar weld joint occurred in the CPAG HAZ near
to the weld interface. The failure occurred by extensive intergranular creep cavity formation. 相似文献
2.
K. Laha K. S. Chandravathi P. Parameswaran Sunil Goyal M. D. Mathew 《Metallurgical and Materials Transactions A》2012,43(4):1174-1186
Evaluations of creep rupture properties of dissimilar weld joints of 2.25Cr-1Mo, 9Cr-1Mo, and 9Cr-1MoVNb steels with Alloy
800 at 823 K were carried out. The joints were fabricated by a fusion welding process employing an INCONEL 182 weld electrode.
All the joints displayed lower creep rupture strength than their respective ferritic steel base metals, and the strength reduction
was greater in the 2.25Cr-1Mo steel joint and less in the 9Cr-1Mo steel joint. Failure location in the joints was found to
shift from the ferritic steel base metal to the intercritical region of the heat-affected zone (HAZ) of the ferritic steel
(type IV cracking) with the decrease in stress. At still lower stresses, the failure in the joints occurred at the ferritic/austenitic
weld interface. The stress-life variation of the joints showed two-slope behavior and the slope change coincided with the
occurrence of ferritic/austenitic weld interface cracking. Preferential creep cavitation in the soft intercritical HAZ induced
type IV failure, whereas creep cavitation at the interfacial particles induced ferritic/austenitic weld interface cracking.
Micromechanisms of the type IV failure and the ferritic/austenitic interface cracking in the dissimilar weld joint of the
ferritic steels and relative cracking susceptibility of the joints are discussed based on microstructural investigation, mechanical
testing, and finite element analysis (FEA) of the stress state across the joint. 相似文献
3.
R. K. Singh Raman 《Metallurgical and Materials Transactions A》1998,29(2):577-586
Microstructural degradations in the base metal adjacent to the weld pool, i.e., the heat-affected zone (HAZ), caused during welding of 2.25Cr-1Mo steel, were characterized by electron and optical microscopy
of different regions of the weldments. In order to study the influence of the microstructural degradations on scaling kinetics
in steam and the resulting subscale features, samples of the base metal, the HAZ, and weld metal specimens were extracted
from the weldment and oxidized in an environment of 35 pct steam+nitrogen at 873 K for 10 hours. Oxide scales formed in the
three regions and the underlying subscales were characterized using scanning electron microscopy (SEM) and electron probe
microanalysis (EPMA). Influence of the “free” chromium content in the three weldment regions on protective scale formation
and on the subscale features has been investigated. As the principal achievement, this study has clearly shown the occurrence
of oxidation-induced void formation in the subscale zone and grain boundary cavitation in the neighboring area during steam
oxidation of the HAZ. This article also discusses the possible role of oxidation-induced void formation and grain boundary
cavitation in the inferior service life of welds in 2.25Cr-1Mo steel components. 相似文献
4.
X. Xu G. D. West J. A. Siefert J. D. Parker R. C. Thomson 《Metallurgical and Materials Transactions A》2018,49(4):1211-1230
The microstructure in the heat-affected zone (HAZ) of multipass welds typical of those used in power plants and made from 9 wt pct chromium martensitic Grade 92 steel is complex. Therefore, there is a need for systematic microstructural investigations to define the different regions of the microstructure across the HAZ of Grade 92 steel welds manufactured using the traditional arc welding processes in order to understand possible failure mechanisms after long-term service. In this study, the microstructure in the HAZ of an as-fabricated two-pass bead-on-plate weld on a parent metal of Grade 92 steel has been systematically investigated and compared to a complex, multipass thick section weldment using an extensive range of electron and ion-microscopy-based techniques. A dilatometer has been used to apply controlled thermal cycles to simulate the microstructures in distinctly different regions in a multipass HAZ using sequential thermal cycles. A wide range of microstructural properties in the simulated materials were characterized and compared with the experimental observations from the weld HAZ. It has been found that the microstructure in the HAZ can be categorized by a combination of sequential thermal cycles experienced by the different zones within the complex weld metal, using the terminology developed for these regions based on a simpler, single-pass bead-on-plate weld, categorized as complete transformation, partial transformation, and overtempered. 相似文献
5.
K. LAHA K.S. CHANDRAVATHI P. PARAMESWARAN K. BHANU SANKARA RAO S.L. MANNAN 《Metallurgical and Materials Transactions A》2007,38(1):58-68
In the postweld heat-treated (PWHT) fusion welded modified 9Cr-1Mo steel joint, a soft zone was identified at the outer edge
of the heat-affected zone (HAZ) of the base metal adjacent to the deposited weld metal. Hardness and tensile tests were performed
on the base metal subjected to soaking for 5 minutes at temperatures below Ac1 to above Ac3 and tempering at the PWHT condition. These tests indicated that the soft zone in the weld joint corresponds to the intercritical
region of HAZ. Creep tests were conducted on the base metal and cross weld joint. At relatively lower stresses and higher
test temperatures, the weld joint possessed lower creep rupture life than the base metal, and the difference in creep rupture
life increased with the decrease in stress and increase in temperature. Preferential accumulation of creep deformation coupled
with extensive creep cavitation in the intercritical region of HAZ led to the premature failure of the weld joint in the intercritical
region of the HAZ, commonly known as type IV cracking. The microstructures across the HAZ of the weld joint have been characterized
to understand the role of microstructure in promoting type IV cracking. Strength reduction in the intercritical HAZ of the
joint resulted from the combined effects of coarsening of dislocation substructures and precipitates. Constrained deformation
of the soft intercritical HAZ sandwich between relatively stronger constitutes of the joint induced creep cavitation in the
soft zone resulting in premature failure. 相似文献
6.
R. K. Singh Raman 《Metallurgical and Materials Transactions A》2000,31(12):3101-3108
Measurement of the thickness of oxide scales that develop over high-temperature components has found an innovative application
in life assessment of steam generation and handling systems. The present study is an investigation of the high-temperature
corrosion and scale thickness across the weldments of a “chromium-molybdenum” steel, and reviews its possible relevance to
the life assessment of the welded high-temperature components by scale thickness measurement. Results are presented of the
recent investigations on the combined roles of the oxidizing environment and secondary carbide precipitation on the extent
of void formation in the microstructurally different regions of weldments of the chromium-molybdenum steel. Specimens of the
weld metal, heat-affected zone (HAZ), and base metal of a 2.25Cr-1Mo steel weldment were oxidized in steam. Extensive internal
oxidation and oxidation-induced void formation (with a much greater intensity in the case of the HAZ) is discussed. The greater
intensity of oxidation-induced void formation in the HAZ may facilitate preferential cracking in this region of the weldments
and, hence, is proposed to be an important parameter in the context of the recently developed codes for life assessment of
aging high-temperature components. 相似文献
7.
R. K. Singh Raman 《Metallurgical and Materials Transactions A》1999,30(8):2103-2113
This study is an attempt to understand the combined role of variations in oxidizing environment and secondary precipitation,
in the microstructurally different regions of a standard Cr-Mo steel weldment, on the intensity of internal oxidation during
high-temperature oxidation in air and steam environments. Samples of the weld-metal, heat-affected zone (HAZ), and base-metal
regions were separated from the weldment of 2.25Cr-1 Mo steel and oxidized in the environments of air and steam at 873 K.
The oxide scales and underlying subscales were characterized using scanning electron microscopy (SEM), energy-dispersive X-ray
(EDX) analysis, and electron probe microanalysis (EPMA). Extensive internal oxidation and oxidation-induced void formation
in the subscale zone and grain-boundary cavitation in the neighboring region were found to occur during oxidation in the steam
environment. However, the internal oxidation and void formation were much more extensive in the subscale regions of the HAZ
than in the subscales of the weld-metal and base-metal regions. As a result, the alloy matrix in the area neighboring the
subscale region of the HAZ specimen suffered extensive grain-boundary cavitation. This behavior has been attributed to a rather
specific combination and complex interplay of the environment, alloy microstructure, oxidizing temperature, and nature of
the resulting external scale in causing and sustaining internal oxidation. The article also discusses the role of internal
oxidation-assisted microstructural degradation in deteriorating the service life of components of 2.25Cr-1Mo steel. 相似文献
8.
C. R. Das S. K. Albert J. Swaminathan S. Raju A. K. Bhaduri B. S. Murty 《Metallurgical and Materials Transactions A》2012,43(10):3724-3741
The roles of boron and heat-treatment temperature in improving the type IV cracking resistance of modified 9Cr-1Mo steel weldment were studied. Two different heats of P91 steel, one without boron, designated as P91 and the other with controlled addition of boron with very low nitrogen, designated as P91B, were melted for the current study. The addition of Boron to modified 9Cr-1Mo steel has increased the resistance against softening in fine-grained heat-affected zones (FGHAZ) and intercritical heat-affected zones (ICHAZ) of the weldment. Creep rupture life of boron containing modified 9Cr-1Mo steel weldment, prepared from 1423?K (1150?°C) normalized base metal, was found to be much higher than that prepared from 1323?K (1050?°C) normalized base metal because of the stabilization of lath martensite by fine M23C6 precipitates. This finding is in contrast to the reduction in creep rupture life of P91 weldment prepared from 1423?K (1150?°C) normalized base metal compared with that of the weldment prepared from 1323?K (1050?°C) normalized base metal. The trace of failure path from the weld metal to ICHAZ in P91B weldment was indicative of type II failure in contrast to type IV failure outside the HAZ and base metal junction in P91 weldment, which suggested that boron strengthened the microstructure of the HAZ, whereby the utilization of boron at a higher normalizing temperature seemed to be significantly greater than that at the lower normalizing temperature. 相似文献
9.
K. N. Gowtham M. Vasudevan V. Maduraimuthu T. Jayakumar 《Metallurgical and Materials Transactions B》2011,42(2):385-392
Modified 9Cr-1Mo ferritic steel is used as a structural material for steam generator components of power plants. Generally,
tungsten inert gas (TIG) welding is preferred for welding of these steels in which the depth of penetration achievable during
autogenous welding is limited. Therefore, activated flux TIG (A-TIG) welding, a novel welding technique, has been developed
in-house to increase the depth of penetration. In modified 9Cr-1Mo steel joints produced by the A-TIG welding process, weld
bead width, depth of penetration, and heat-affected zone (HAZ) width play an important role in determining the mechanical
properties as well as the performance of the weld joints during service. To obtain the desired weld bead geometry and HAZ
width, it becomes important to set the welding process parameters. In this work, adaptative neuro fuzzy inference system is
used to develop independent models correlating the welding process parameters like current, voltage, and torch speed with
weld bead shape parameters like depth of penetration, bead width, and HAZ width. Then a genetic algorithm is employed to determine
the optimum A-TIG welding process parameters to obtain the desired weld bead shape parameters and HAZ width. 相似文献
10.
The kinetics of hydrogen attack (HA) has been studied in the heat affected zone (HAZ) in a 2.25Cr-1Mo steel weld to determine
the relative rates of attack and bubble nucleation in the HAZ, base metal, and weld metal. The HAZ was found to suffer hydrogen
attack at nearly twice the rate of the base metal, but not as rapidly as the weld metal. Nucleation of bubbles does not occur
during HA of the HAZ of a 2.25Cr-1Mo steel, on exposure to hydrogen pressure of 20.5 MPa or less, but does occur at higher
pressures up to 31.5 MPa (4500 psi) at 550 °C, or up to 27.5 MPa (4000 psi) at 580 °C. Such nucleation results in enhancement
of the HA rate by a factor of six. The weak dependence of nucleation effects on hydrogen pressure and the saturation of the
nucleation effects in a short time suggest some thermally activated nucleation of fresh bubbles.
Formerly with The Ohio State University. 相似文献
11.
Sunil Goyal K. Laha K. S. Chandravathi K. Bhanu Sankara Rao 《Transactions of the Indian Institute of Metals》2010,63(2-3):461-466
Creep tests were carried out on 2.25Cr-1Mo ferritic steel base metal and its fusion welded joint at 823 K over a stress range of 100–240 MPa. The weld joint possessed lower creep rupture strength than the base metal and the reduction was more at lower applied stresses. The failure occurred in the intercritical region of heat-affected zone (HAZ) of the joint, commonly known as Type IV cracking. Type IV cracking in the joint was manifested as pronounced localization of creep deformation in the soft intercritical region of HAZ coupled with preferential creep cavitation. The creep cavitation in intercritical HAZ was found to initiate at the central region of the creep specimen and propagate outwards to the surface. To explain the above observations, the stress and strain distributions across the weld joint during creep exposure were estimated by using finite element analysis. For this purpose creep tests were also carried out on the deposited weld metal and simulated HAZ structures (viz. coarse-grain structure, fine-grain structure, and intercritically annealed structure) of the joint. Creep rupture strength of different constituents of joint were in the increasing order of intercritical HAZ, fine-grain HAZ, base metal, weld metal and coarse-grain HAZ. Localized preferential creep straining in the intercritical HAZ of weld joint as observed experimentally was supported by the finite element analysis. Estimated higher principal stress at the interior regions of intercritical HAZ explained the pronounced creep cavitation at these regions leading to Type IV failure of the joint. 相似文献
12.
Manidipto Mukherjee Tapan Kumar Pal 《Metallurgical and Materials Transactions A》2012,43(6):1791-1808
This article describes in detail the effect of the modes of metal transfer on the microstructure and mechanical properties
of gas metal arc-welded modified ferritic stainless steel (SSP 409M) sheets (as received) of 4 mm thickness. The welded joints
were prepared under three modes of metal transfer, i.e., short-circuit (SC), spray (S), transfer, and mix (M) mode transfer using two different austenitic filler wires (308L and
316L) and shielding gas composition of Ar + 5 pct CO2. The welded joints were evaluated by means of microstructural, hardness, notched tensile strength, Charpy impact toughness,
and high cycle fatigue. The dependence of weld metal microstructure on modes of metal transfer and filler wires has been determined
by dilution calculation, WRC-1992 diagram, Creq/Nieq ratio, stacking fault energy (SFE), optical microscopy (OM), and transmission electron microscopy (TEM). It was observed
that the microstructure as well as the tensile, Charpy impact, and high cycle fatigue of weld metal is significantly affected
by the mode of metal transfer and filler wire used. However, the heat-affected zone (HAZ) is affected only by the modes of
metal transfer. The results have been correlated with the microstructures of weld and HAZ developed under different modes
of metal transfer. 相似文献
13.
Muhammad Atif Makhdoom Muhammad Kamran Gul Hameed Awan Sehrish Mukhtar 《Metallurgical and Materials Transactions A》2013,44(12):5505-5512
Shielded metal arc welding was applied to AISI 1045 medium carbon steel. The microstructural changes and electrochemical corrosion behavior of the heat-affected zone (HAZ), base metal (BM), and weld zone (WZ) were investigated. The effect of welding passes on microstructural changes of BM, HAZ, and WZ were elucidated using optical microscopy, potentiodynamic Tafel scan, and linear polarization resistance (LPR) methods in plain water and 3.5 pct (w/v) NaCl solution under standard temperature and pressure using corrosion kinetic parameters. From microstructural observations, the variations in ferrite morphology in the BM and WZ showed dissimilar electrochemical corrosion behavior and a corrosion rate than that of HAZ. 相似文献
14.
P. K. Liaw M. G. Burke A. Saxena J. D. Landes 《Metallurgical and Materials Transactions A》1991,22(2):455-468
Elevated-temperature fracture toughness properties were developed on ex-service 2-l/4Cr-1Mo steel weldments. Fracture toughness
was measured on both base and heat-affected zone (HAZ) metals. A composite specimen consisting of base, HAZ, and weld metals
was used to develop fracture toughness properties in the HAZ area. It was observed that the J-R curve of the HAZ was significantly
lower than that of the base metal. Increasing crack extension increased the difference between theJ-R curves of the base metal and the HAZ. Dimpled fracture was the prime fracture mode in the base metal specimen, and a mixed-mode
(ductile and “granular”) fracture was found in the HAZ specimens. Scanning transmission electron microscopy (STEM) examination
revealed significant intergranular carbide precipitation and agglomeration within the HAZ. The lower fracture toughness of
the HAZ, as compared to the base metal, was attributed to the large accumulation of carbides in the grain boundaries of the
HAZ, which weakened the grain boundaries and caused “granular” fracture. 相似文献
15.
J. T. Al-Haidary A. A. Wahab E. H. Abdul Salam 《Metallurgical and Materials Transactions A》2006,37(11):3205-3214
The fatigue crack propagation rate (FCPR) in 316L austenitic stainless steel (ASS) and its weldments was investigated, at
two loading amplitudes, 7 and 8.5 kN, under tension-tension mode. Two welding techniques, submerged arc welding (SAW) and
manual arc welding (MAW), have been used. Magnetic δ-ferrite, depending upon Ni and Cr content in the metal, in the weld zone
upon solidification was considered. The ferrite number (FN) of δ-ferrite formed in the SAW zone was much higher (maximum 9.6)
compared to the corresponding value (maximum 0.75) in the MAW zone. A fatigue starter notch was positioned at different positions
and directions with respect to the weld zone, in addition to the heat-affected zone (HAZ). Regions of high and low FCPRs as
the fatigue crack propagated through and across the weld zone have been noticed. This is related to the direction of the tensile
residual stresses present in weld zone, resulting from solidification of the weld metal. The FCPR was higher along through
the HAZ and weld zone because of the microstructural change and direction and distribution of tensile residual stresses. The
FCPR was much lower when crack propagated perpendicular to the weld zone, particularly in the case of SAW in which higher
δ-ferrite volume fraction was noticed. A lower FCPR found across the weld zone, in both SAW and MAW, was accompanied by rubbed
areas in their fractures. 相似文献
16.
Ferritic steels are often used in thick-plate form. The feasibility of electron-beam welding such thick plates and the mechanical
properties of these welds were examined in a recent study. In this investigation, the microstructures of these thick-plate,
electron-beam welds were evaluated. The study was carried out on a 3Cr-1.5Mo-0.1V steel. Weld simulations were used to aid
in the study of the heat-affected zone (HAZ) microstructure. Such simulations allowed for a more reliable and detailed evaluation
of the variation in microstructure with distance from the fusion line. The structures were related to microhardness measurements
made across the width of the weld and the HAZ. The fusion zone and the immediately adjacent HAZ consisted of bainite platelets
with narrow films of retained austenite at many of the bainite platelet boundaries. Farther away from the fusion zone, the
structure was a two-phase mixture of bainitic platelets and ferrite produced by heating base metal between theAc
1 and theAc
3 temperatures. Still farther from the weld, the structure consisted of tempered bainite, with the degree of tempering decreasing
with distance from the fusion line. The bainite plus ferrite region and the tempered bainite section are associated with a
soft zone in the hardness profile across the weld. A postweld heat treatment (PWHT) was found to reduce the hardnesses of
the fusion zone, HAZ, and base material to relatively uniform levels. The structure across the weld and HAZ after a PWHT is
tempered bainite except in one section of the HAZ in which tempered bainite and ferrite coexist. 相似文献
17.
The present study has been carried out to investigate the coarse-grained heat-affected zone (CGHAZ) microstructure and crack
tip opening displacement (CTOD) toughness of grade StE 355 Ti-microalloyed offshore steels. Three parent plates (40-mm thick)
were studied, two of which had Ti microalloying with either Nb + V or Nb also present. As a third steel, conventional StE
355 steel without Ti addition was welded for comparison purposes. Multipass tandem submerged arc weld (SAW) and manual metal
arc weld (SMAW) welds were produced. Different heat-affected zone (HAZ) microstructures were simulated to ascertain the detrimental
effect of welding on toughness. All HAZ microstructures were examined using optical and electron microscopy. It can be concluded
that Ti addition with appropriate steel processing, which disperses fine TiN precipitates uniformly, with a fine balance of
other microalloying elements and with a Ti/N weight ratio of about 2.2, is beneficial for HAZ properties of StE 355 grade
steel. 相似文献
18.
R. K. Singh Raman 《Metallurgical and Materials Transactions A》1995,26(7):1847-1858
In order to study the influence of microstructural variation on the oxidation of the weldment of 2.25Cr-1Mo steel, regions
with different microstructures were identified by optical microscopy. The weld metal, the base metal, and the heat-affected
zone (HAZ), as well as the subzones within the HAZ, i.e., the intercritical (ICR), the fine-grain bainite (FGB), and the coarse-grain
bainite (CGB) regions were separated from the weldment by precise steps of metallography. Transmission electron microscopic
examinations for the identification of the secondary phases in microstructurally different regions and subzones have suggested
that M23C6 and M7C3 pre-cipitates form predominantly in the subzones of HAZ, whereas the Mo2C type of carbide forms exclusively in the weld-metal and base-metal regions of the weldment. However, population and distribution
of the secondary phases were different in the three subzones of the HAZ. In order to understand the influence of these microstructural
variations on the oxidation behavior, the various regions and subzones were oxidized at 773 and 873 K. The HAZ and its constituents
were found to oxidize at much higher rates than the weld metal and the base metal. Relative compositions and morphologies
of the scales were compared by scanning electron microscopy with energy-dispersive analyses of X-rays (SEM/EDX), and secondary
ion mass spectrometry (SIMS). Scale formed over the weld metal shows a greater tendency for spallation, as suggested by tests
monitoring acoustic emission. X-ray diffraction (XRD) patterns of the scales over these specimens were taken. Results of the
SEM/EDX, SIMS, and XRD investigations suggest for-mation of inner scales with less Cr(i.e., less protective) over the HAZ than over the weld-metal and the base-metal regions. Variation in the Cr contents of the scales
formed over the various regions is proposed to arise from the difference in microstructural features in different regions
of the weldments.
Formerly with the Metallurgy Division, Indira Gandhi Centre for Atomic Research, Kalpakkan, India 相似文献
19.
Microstructural development of bainitic ferrite under a simulated weld heat-affected zone (HAZ) of low-carbon steel was correlated with the characteristics of martensite-austenite (M-A) constituent. By combining laser scanning confocal microscopy (LSCM) observations and electron backscatter diffraction (EBSD) analysis, we evaluated variant pair formation in time-series, which was related to the second-phase formation phenomenon. Furthermore, the classification of the microstructural development showed that the characteristics of M-A in a weld HAZ can be predicted from the microstructural development of bainitic ferrite. 相似文献
20.
Toshihiko KOSEKI 《Baosteel Technical Research》2010,(Z1):19
The reliability of steel welds becomes more critical issue with increasing steel strength,because brittle phases are more likely to form in the weld metals and heat-affected zone(HAZ) and thereby the toughness and ductility of the welds are degraded.Therefore,refinement of microstructure and minimization of the brittle phases are necessary to improve the reliability of the high-strength steel welds.In this presentation,microstructure formation that controls the toughness of weld metals and HAZ in high-strength low-alloy(HSLA) steel welds is reviewed and possible routes to the improvement of the weld microstructure and weld toughness are discussed. 相似文献