scholarly journals EVALUASI HASIL HARDFACING ELEKTRODA HV 350 PASCA QUENCHING MEDIA AIR, COOLANT DAN OLI

2019 ◽  
Vol 4 (2) ◽  
pp. 104-107
Author(s):  
Sopiyan Sopiyan ◽  
Syamsuir Syamsuir ◽  
Yos Nofendri
Keyword(s):  
Surface Hardening ◽  
Welding Process ◽  
High Hardness ◽  
Parent Metal ◽  
Quenching Media

AbstrakTeknik hardfacing merupakan pengerasan permukaan dengan menambahkan unsur atau lapisan terertentu agar sifat logam induk menjadi lebih keras. Pada blade buldozer umumnya dikeraskan dengan memberikan lapisan hasil pengelasan dengan elektroda khusus. Elektroda tersebut memiliki sifat kekerasan yang tinggi, sehingga blade pada buldozer tidak cepat aus. Dalam penelitian ini akan dilakukan dua kali proses quenching. Pertama dengan menggunakan air ketika selesai proses pengelasan. Kemudian dilanjutkan dengan pemanasan kembali dalam tungku kemudian dilanjutkan dengan proses quenching dengan dua media yang berbeda yaitu oli dan coolant. Dari hasil yang penelitian didapatkan hasil kesimpulan, media coolant merupakan media yang paling optimal dalam meningkatkan kekerasan dari hasil hardfacing. Nilai kekerasan yang didapatkan dari hasil pencelupan dengan media coolant adalah sebesar 299,73 HV Kata kunci: Hardfacing, HV 350, Quenching dan Kekerasan AbstractHardfacing technique is surface hardening by adding certain elements or layers so that the nature of the parent metal becomes harder. On the bulldozer blade is generally hardened by giving a layer of welding results with special electrodes. The electrode has high hardness properties, so the blade of the bulldozer does not wear out quickly. In this research two quenching processes will be carried out. First by using water when the welding process is complete. Then proceed with reheating in the furnace then proceed with the process of quenching with two different media namely oil and coolant. From the results of the study concluded, coolant media is the most optimal media in increasing the hardness of the results of hardfacing. The hardness value obtained from the dyeing with coolant media is 299.73 HV Keywords: Hardfacing, HV 350, Quenching and Hardness

Microstructural Effects between AHSS Dissimilar Joints Using MIG and TIG Welding Process

2015 ◽  
Vol 1766 ◽  
pp. 29-35 ◽  
Author(s):  
G.Y. Pérez Medina ◽  
M. Padovani ◽  
M. Merlin ◽  
A.F. Miranda Pérez ◽  
F.A. Reyes Valdés
Keyword(s):  
Arc Welding ◽  
Gas Metal Arc Welding ◽  
Welding Process ◽  
High Hardness ◽  
Inert Gas ◽  
Mechanical Degradation ◽  
Low Alloy Steels ◽  
Dissimilar Joints ◽  
Lap Shear ◽  
Welding Processes

ABSTRACTGas tungsten arc welding-tungsten inert gas (GTAW-TIG) is focused in literature as an alternative choice for joining high strength low alloy steels; this study is performed to compare the differences between gas metal arc welding-metal inert gas (GMAW-MIG) and GTAW welding processes. The aim of this study is to characterize microstructure of dissimilar transformation induced plasticity steels (TRIP) and martensitic welded joints by GMAW and GTAW welding processes. It was found that GMAW process lead to relatively high hardness in the HAZ of TRIP steel, indicating that the resultant microstructure was martensite. In the fusion zone (FZ), a mixture of phases consisting of bainite, ferrite and small areas of martensite were present. Similar phase’s mixtures were found in FZ of GTAW process. The presence of these mixtures of phases did not result in mechanical degradation when the GTAW samples were tested in lap shear tensile testing as the fracture occurred in the heat affected zone. In order to achieve light weight these result are benefits which is applied an autogenous process, where it was shown that without additional weight the out coming welding resulted in a high quality bead with homogeneous mechanical properties and a ductile morphology on the fracture surface. Scanning electron microscopy (SEM) was employed to obtain information about the specimens that provided evidence of ductile morphology.

Water-Jet Assisted Laser Surface Hardening of Medium Carbon Steel Using Fiber Laser

2018 ◽  
Author(s):  
Sagar Sarkar ◽  
Ashish Kumar Nath
Keyword(s):  
Surface Hardening ◽  
High Hardness ◽  
Medium Carbon Steel ◽  
Water Jet ◽  
Laser Surface ◽  
Peak Hardness ◽  
Bottom Surface ◽  
Thin Sheets ◽  
Laser Surface Hardening ◽  
Conventional Laser

Laser surface hardening of most of the industrial components require depth of surface modification in the range of 100–150 micron. Conventional laser surface hardening uses laser as a heat source to modify a particular area of the surface without melting in an inert gas environment. However, the hardened profile in this case shows peak hardness value at a certain depth from the top surface. Also, hardening the top surface to get relatively much higher hardness near the top surface in case of thin sheets becomes difficult due to accumulation of heat below the surface of the specimen which in turn lowers the cooling rate. Hence, self-quenching becomes inadequate. In the present study, an in-house fabricated laser processing head with coaxial water nozzle has been used to flow a laminar water-jet during the laser surface hardening process to induce forced convection at the top surface. Thus, heat gets carried away by the water-jet from the top surface and by the water from the bottom surface as well. Results show that with judicious selection of process parameters, it is possible to get higher hardness (800 HV) to that of conventional laser surface hardening (500 HV) at the top surface using this process. Present process can be used for those cases where high hardness values are required near the top surface specially for thin sheets and thermally sensitive materials.

Nickel Base Alloy Powder Spray Welding Process Application in Production

2013 ◽  
Vol 813 ◽  
pp. 129-131
Author(s):  
Yu Hai Xu ◽  
Yu Ping Zhao
Keyword(s):  
Alloy Powder ◽  
Base Alloy ◽  
Welding Process ◽  
Slag Inclusion ◽  
Thin Coating ◽  
Nickel Base Alloy ◽  
Parent Metal ◽  
Workpiece Surface ◽  
Welding Technology ◽  
Nickel Base

In this paper, we study Spray welding technology has been widely used in our country, it is between the spraying and welding process, the workpiece surface after spray welding coating is thin and smooth, dilution rate is extremely low, the deposited layer and base metal metallurgy, high bonding strength, density, and coating no slag inclusion, porosity and oxidation is suitable for occasions with thin coating. In 45Mn parent metal, for example, this paper mainly introduces the application of the technology in production.

Wet Welding as a “Serious” Repair Procedure?

1998 ◽  
Vol 120 (3) ◽  
pp. 191-196 ◽  
Author(s):  
P. Szelagowski
Keyword(s):  
Welding Process ◽  
High Hardness ◽  
Field Application ◽  
Oil Field ◽  
Quality Data ◽  
Design Criteria ◽  
High Porosity ◽  
High Hydrogen ◽  
Research Activities ◽  
Welding Processes

Due to intensive and concentrated research activities during the last 10 to 15 yr, the quality of wet-welded joints has been improved to an extent that this process is currently regarded as a potential alternative to the more costly dry hyperbaric welding processes in comparable water depths. The wet welding process has matured to an interesting alternative repair process due to its high flexibility and versatility and its low investment costs with respect to achieving comparable weldment quality. However, due to the previous bad reputation of the poor weldment quality in former times, related to extremely high hardness, high porosity, high hydrogen contamination, and, in combination with this, high cracking susceptibility, the wet welding process still requires concentrated activities to improve its reputation and credibility, especially in European oil field application. New acceptance creiteria, more detailed information on the achievable weldment quality, and especially the development of life-predicting data for wet-welded components on the one hand, and new design criteria especially related to the process application in wet environment as well as excellent training of diver welders on the other hand, have been required. Advanced testing methods had to be applied, additional design criteria had to be developed, and achievable weldment quality data had to be included in acknowledged and approved standards and recommendations in training and certification standards for diver welders. All these data are now available. These results have been achieved with the financial support of the European Community through the THERMIE PROJECT FUNDING.

About weldability and welding of Al alloys: case study and problem solving

2017 ◽  
Vol 2 (85) ◽  
pp. 67-74 ◽  
Author(s):  
E. Fracchia ◽  
F. Gobber ◽  
M. Rosso
Keyword(s):  
Mechanical Properties ◽  
Welding Process ◽  
Optical Microscope ◽  
Sem Analysis ◽  
Al Alloys ◽  
Hot Tearing ◽  
Parent Metal ◽  
Oxide Inclusions ◽  
Welding Processes

Purpose: Among many disciplines within engineering, welding is probably one of the most inexact – rather more of an art than a science. As weldment is meant the complete joint comprising the weld metal, heat affected zones (HAZ) and the adjacent parent metal and should have the same properties as the parent metal. This paper aims provides a basic understanding of the metallurgical principles involved in how aluminium alloys achieve their strength and how welding can affect these properties. The most important and applied welding processes to Al alloys are here shortly introduced, as well as the preparation of parent metals prior to welding and good welding practice to avoid and/or keep under control defects and failures. Some case studies with possible failures will be introduced together with actions and suggestions to solve the observed problems. Design/methodology/approach: Two sheets of the EN AW 5454 (AlMg3Mn) alloy were weld with resistance welding process and after a mechanical processing of lamination was observed the presence of the defect. The microstructure of the defect as well as the welded part were evaluated with stereomicroscope (LEICA MS5), optical microscope (LEICA MEF4M), and with SEM analysis (LEO 1540 VP equipped with an energy dispersive X-ray spectroscope Oxford Link Pentafet). Findings: The well welded part was analysed with optical microscopy and electronic microscopy resulting with the attended mechanical properties. Micro-hardness indentations on the joint demonstrated the good mechanical properties of the joint while with the microscopic observations were identified the orientation and presence of precipitates typical of this alloy. In the defect, microscopically observations showed the presence of oxide inclusions. Research limitations/implications: There are a number of problems associated with the welding of aluminium and its alloys that make it difficult to achieve this ideal. The features and defects that may contribute to the loss of properties comprise the following: gas porosity, oxide inclusions and oxide filming, solidification (hot) cracking or hot tearing, reduced strength in the weld and HAZ, lack of fusion, reduced corrosion resistance and reduced electrical resistance. Originality/value: This case study illustrated clearly the importance of the cleaning on the surfaces to obtain a well welded joint ensuring the desired mechanical properties.

Microstructure and Wear Resistance of Hard-Facing Weld Metal on JIS-S50C Carbon Steel in Agricultural Machine Parts

2016 ◽  
Vol 872 ◽  
pp. 55-61 ◽  
Author(s):  
Kittipong Kimapong ◽  
Pramote Poonayom ◽  
Voraya Wattanajitsiri
Keyword(s):  
Mechanical Properties ◽  
Wear Resistance ◽  
Carbon Steel ◽  
Weld Metal ◽  
Welding Process ◽  
Welding Current ◽  
High Hardness ◽  
Dilution Effect ◽  
Medium Carbon Steel ◽  
Agricultural Machine

Hard-facing welding is one of the repairing methods for increasing hard metal on the agricultural machine part surfaces that caused by the wear mechanism. To this date, the investigation of an optimized welding process parameter that could produce high hardness and wear resistance of the hard-facing layer is still being developed and performed. This paper aims to study the effects of hard-facing welding layer on mechanical properties and microstructure of hard-facing weld metal on JIS-50C carbon steel. The summarized results are as follows: (a) an increase of hard-facing layer affected to increase the hardness of the layer, (b) the hardness of the welds showed a maximum hardness of about 750 HV at a top surface of 3rd welds layers with no-buffering layer and showed the minimum hardness of about 225 HV at a base metal, (c) microstructure investigation showed that the increase of the phase that contained higher chromium, molybdenum and manganese affected the increase of the hardness and the wear resistance of the weld metal, (d) The minimum mass loss of 0.2559 mg/m could be found when a welding current of 100A, non-buffering layer and 3 layers of hard-facing weld metal were applied, and (e) the buffering layer was able to produce a sound weld metal and might not be suited for the hard-facing welding of the medium carbon steel because it produced the dilution effect that deteriorated the mechanical properties of the weld metal.

The Effect of the Laser Surface Treatments on the Wear Resistance

2010 ◽  
Vol 649 ◽  
pp. 107-112 ◽  
Author(s):  
Enikő Bitay ◽  
Tünde Kovács
Keyword(s):  
Wear Resistance ◽  
Surface Hardening ◽  
Laser Scanning ◽  
Base Material ◽  
High Hardness ◽  
Surface Melting ◽  
Laser Surface ◽  
Surface Alloys ◽  
Phase Dispersion ◽  
Treatment Technologies

In case of traditional surface-hardening processes (e.g. carburization), the wear resistance usually correlates with hardness, which means optimising these technologies could be based on testing the achieved hardness. In case of modern laser treatment technologies however – e.g. surface melting combined with surface alloys or laser scanning surface treatment followed by nitridation – it is unlikely to conclude wear resistance from the value of hardness. The reasons are the following: the hardness of surface melting combined with surface alloys (especially if alloyage is made using high hardness compound powders) depends on the remelting of the material and the particle size and distribution of the dispersed alloy. These same properties define wear resistance, but the values don’t necessarily correlate. In case of a compound phase dispersion in a softer base material, we can have outstanding wear resistance with moderate hardness. (e.g. bearing metals) The case is similar with scanning treatment combined with nitridation, which results in complicated structures. Due to the above, it is possible that in order to optimise these aforementioned technologies, we have to rely on examining wear resistance. In order to back this statement, we show the results of two typical experiments concerning these technologies.

Study on the Surface Plasma Hardening Treatment and Anti-Penetration Mechanism of Armor Steel

2013 ◽  
Vol 690-693 ◽  
pp. 2141-2144
Author(s):  
Kai Ping Yu ◽  
Feng Wang ◽  
Rong Gang Chen ◽  
Jun Jun Zong
Keyword(s):  
Surface Hardening ◽  
Protective Layer ◽  
High Hardness ◽  
Surface Plasma ◽  
Hardening Process ◽  
Plasma Transferred Arc ◽  
Hardening Treatment ◽  
Penetration Ability ◽  
Penetration Mechanism ◽  
Armor Steel

Plasma surface hardening process was performed to improve the surface on the 22SiMn2TiB steel by plasma transferred arc. Experiments were carried out to characterize the hardening qualities. The anti-penetration ability and mechanism were analyzed, and hardness protective layer can improve greatly the ability of armor protection. The dual hardness armor steel composed of high hardness panel and basic backplane was developed based on the experimental results.

scholarly journals Analysis of the coefficient of linear relationship, generated by the exponential heating during the welding process for an A36 steel plate

2021 ◽  
pp. 16-21
Author(s):  
Mario Barrera-Moreno ◽  
Rumualdo Servin-Castañeda ◽  
Ismael Calderon-Ramos ◽  
Alejandro Perez-Alvarado
Keyword(s):  
Heat Transfer ◽  
Steel Plate ◽  
Welding Process ◽  
High Hardness ◽  
Metal Plate ◽  
Filler Material ◽  
A36 Steel ◽  
Welding Sequences ◽  
Relationship Of ◽  
The Relationship

The present study presents the relationship of temperature and deformation as well as the analysis of heat transfer and deformation produced during welding of a steel plate. The method consists of strategically welding a base metal plate (A-36) with a high-hardness filler material to obtain an overall increment in wear resistance. However, the thermal cycles generated during welding produced deformation, thus changing the flatness of the plate. Different sequences of welding were applied to obtain a relationship between the heat transfer and deformation. A filler material was applied to 100 holes (1/2” diameter and 8 mm depth) in a ½” steel plate. The temperature and deformation were measured for 3 different welding sequences. Plate 1 reached a final mean temperature of 467 °C and deformation of 0.016”, plate 2 reached 472.9 °C and -0.008”, and plate 3 reached 354.2 °C and 0.020”. The results indicate that the deformation is not function of the final temperature, instead the deformation is function of the slope of the curve temperature vs deformation. The behavior of the curve temperature vs deformation is linear for all cases studied, confirming the findings of the lowest deformation for plate 2 which exhibited the lowest slope.

Study on Welding Techniques of 316L Lined Bimetallic Pipe

2019 ◽  
Vol 944 ◽  
pp. 944-949
Author(s):  
Fa Gen Li ◽  
Xun Ji Li ◽  
Wei Wei Li ◽  
Xian Ming Li ◽  
Ze Liang Chang ◽  
...  
Keyword(s):  
Corrosion Resistance ◽  
Failure Analysis ◽  
Research Work ◽  
Welding Process ◽  
High Hardness ◽  
Gas Production ◽  
Structure Design ◽  
Cored Wire ◽  
Welding Defects ◽  
Weld Corrosion

It is well known that welding technique was often a knotty problem for bimetallic lined steel pipes to use widely. A number of failures in secession of weld cracking and weld corrosion had been observed in oil fields in recent years, which seriously disrupted the order of oil and gas production. To solve welding problems of 316L bimetallic lined pipes, works outcome about failure analysis and welding process research were presented in this paper. Failure analysis results confirmed that Welding defects, high hardness regions was the main reasons about failure problems of weld crack while structure design defects of seal weld and bad back-protection effects of flux-cored wire resulted in weld corrosion. Welding defects in the regions of seal weld became the failure source while the high hardness both in the region of seal weld and weld joint formed the crack propagation channel, and therefore both initially contributed to weld cracking. Additionally owing to the structure design of seal weld, liner layer would be heated over and over again during the period of seal weld and then it was not enough to protect CRA layers from being damaged during the period of girth weld. As a result the corrosion resistance in the welding area was reduced to become a weak area. On the basis of failure analysis, further research work was carried out to improve welding performance. Seal weld structure and girth weld process was improved. The difference of welding wires and welding process was analyzed, and their defects were described separately. Results showed that the welding performance welding by ERNiCrMo-3 and supporting technology was more reliable than ATS-F309L and supporting technology, whether seal weld or butt welding. The distribution and value of the hardness could be effectively controlled; Moreover, corrosion resistance performance was also better. Therefore, the seal weld and girth weld conducted by ERNiCrMo-3 and supporting technology was feasible.

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