• Proceedings of the KWS Conference
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• 2006.05a
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• pp.133-134
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• 2006

The welding consumables which are able to be applied in shipbuilding is decided in accordance with base materials. The class societies regulate that 3Y grade welding consumables have to be used for E(H) grade steel. Welding consumables with about 1.5% Ni contents in the deposited metal have been using to weld E(H) grade steel in domestic shipbuilding companies. It was inevitable to obtain impact property of weldment at low temperature. However, when the welding consumables are used in production, there are two kinds of problems-bad workability & cost-up of welding consumables. Therefore development of Ni free welding consumables for E(H) grade steel are required & this paper will introduce the development of Ni free 4Y grade FCW.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.16 no.6
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• pp.465-470
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• 2003

The chemical mechanical polishing (CMP) process has been widely used for the global planarization of multi-layer structures in semiconductor manufacturing. The CMP process can be optimized by several parameters such as equipment, consumables (pad, backing film and slurry), process variables and post-CMP cleaning. However, the COO(cost of ownership) is very high, because of high consumable cost. Especially, among the consumables, the slurry dominates more than 40 %. In this paper, we have studied the CMP characteristics of diluted silica slurry by adding of raw alumina abrasives and annealed alumina abrasives. As an experimental result, we obtained the comparable slurry characteristics compared with original silica slurry in the view-point of high removal rate and low non-uniformity. Therefore, we can reduce the cost of consumables(COC) of CMP process for ULSI applications.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2003.05d
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• pp.105-108
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• 2003

CMP(chemical mechanical polishing) process has been attracted as an essential technology of multi-level interconnection. However, the COO(cost of ownership) is very high, because of high consumable cost. Especially, among the consumables, slurry dominates more than 40 %. So, we focused how to reduce the consumption of raw slurry. In this paper, We have studied the CMP (chemical mechanical polishing) characteristics of slurry by adding of raw alumina abrasive and annealed alumina abrasive. As a experimental results, we obtained the comparable slurry characteristics compared with original silica slurry in the view point of high removal rate and low non-uniformity. Therefore, we can reduce the cost of consumables(COC) of CMP process for ULSI applications.

• Journal of Welding and Joining
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• v.34 no.6
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• pp.11-15
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• 2016

YP 690MPa grade steels are used as the main structural steel for offshore structure such as Jack-up Rig and WTIV(Wind Turbine Installation Vessel). Most of welding consumables applied to YP 690MPa grade steels are basic type flux cored wires that shows the poor weldability and not suitable for all position welding. For this reason, welding consumables with rutile type flux system is required. Rutile type flux cored wires show excellent weldability and apply to all position welding. This paper presents the mechanical properties of weld metal with rutile type flux cored wire developed and finally assessed the possibility for application.

• Proceedings of the KWS Conference
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• 2009.11a
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• pp.40-40
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• 2009

The Cu-bearing PFS-700 steel which has yield strength over 700 MPa was developed to replace the existing submarine structural material, HY-100. PFS-700 steel has good combination of mechanical properties and superior weldability which can be welded without pre-heating before welding. Application PFS-700 steel to submarine or battle ship will give a great reduction of cost by removing or lowing pre-heating. To develop pre-heat free welding consumables that matches and take advantage of PFS-700 steel, new welding consumables have been designed for the GMAW, SAW processes and explosion bulge test(EBT) were conducted to see the reliability of welded structure. All welding was conducted without pre-heating before welding, the inter-pass temperatures were below $50^{\circ}C$ for SAW50 and $150^{\circ}C$ for GMAW and SAW150. All EBT specimens show over 14% reduction of thickness without through-thickness crack or propagation of crack to the hole-down area. Tensile properties for all welding conditions show higher(GMAW) or similar values(SAW50, SAW150) to the base metal. Charpy impact values for the weld metal also show 163.5J(GMAW), 95.4J(SAW50) and 69.0J(SAW150), which meet the goal, 50J, of this project.

• Journal of Welding and Joining
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• v.27 no.6
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• pp.80-86
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• 2009

The Cu-bearing PFS-700 steel which has yield strength over 700 MPa was developed to replace the existing submarine structural material, HY-100. The PFS-700 steel has a combination of good mechanical properties and superior weldability. Becaus of that, it can be welded without pre-heating. The application of PFS-700 steel to submarine or battle ship will give a great reduction of cost by omitting pre-heating or lowering pre-heat temperature. To develop pre-heating free welding consumables that match and take advantage of PFS-700 steel, new welding consumables have been designed for the GMAW, SAW processes and explosion bulge test(EBT) was conducted to see the reliability of welded structure. All welds were made without pre-heating, and the inter-pass temperature was below $50^{\circ}C$ for SAW50 and $150^{\circ}C$ for GMAW and SAW150. All EBT specimens show over 14% thickness reduction without through-thickness crack or crack propagation to the hole-down area. Tensile properties for all welding conditions show higher(GMAW) or similar values(SAW50, SAW150) to the base metal. Charpy impact values for the weld metal also show 163.5J(GMAW), 95.4J(SAW50) and 69.0J(SAW150), which meet the goal(higher than 50J) of this project.

• Journal of Welding and Joining
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• v.28 no.2
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• pp.79-83
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• 2010

In this study, newly developed welding consumables for EGW were welded in EH 36 TM steel plates and their welded joints were evaluated in point of mechanical properties and microstructures compared with imported consumables. Newly developed welding consumables were evaluated as good arc stability and slag fluidity, substantially the same with imported products. The tensile strength of all welded joints were sufficient to meet the requirements specified in a ship’s classification(490~640MPa) and all areas of fracture were heat affected zone(HAZ). Charpy absorbed energy values of all EG welded metals were sufficient to meet the requirements of classification(min. 34J) and those of newly developed wires were evaluated to be better than those of imported wires. As a result observing microstructures of single and tandem EG welded metals through optical and scanning electron microscope (OM&SEM), no grain boundary ferrite(PF(G)) were created in a prior austenite grain boundary and a volume fraction of a fine acicular ferrite were observed very high.

• Journal of Welding and Joining
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• v.34 no.6
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• pp.16-19
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• 2016

Needs for structural integrity procedure such as BS 7910, the nuclear industry document R6 Rev.4 and the European FITNET procedure are being increased in industry. Especially, BS 7910 allows metallic structures to be assessed on the basis of fracture mechanics analysis rather than strict adherence to design and fabricated codes. This study is to propose the flaw assessment to judge the toughness level of welding consumables at the development stage. The FCA welding consumables with YP 690MPa and CTOD over 0.25 mm have been developed and its allowable weld flaw size considering actually applied environment has been evaluated. Since the estimated allowable defect size is sufficiently detectable in nondestructive testing, the toughness of the developed material is judged to be appropriate and no problem in securing the structural integrity.

• Development and Reproduction
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• v.15 no.4
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• pp.385-391
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• 2011

Human in vitro fertilization and embryo transfer (IVF-ET) program is a general procedure for infertile couples since first successful delivery on 1978 in UK and Korean first on 1985. Recently in Korea, more than 42,000 cases per year of IVF-ET were performed and showed good pregnancy rates compared worldwide data. The human IVF-ET procedure use many consumables, such as ovum pick-up (OPU) needles, centrifuge tubes, culture dish, ICSI pipette, culture media and ET catheters. Major of these materials are supported by the global companies. Thus, Korean IVF-ET program might be placed unstable situation by global economical risks. These uncertain problems could be overcome by the domestic production of IVF-ET materials and consumables. Two times questionnaires for Korean clinicians and researchers about the domestic production were performed and analyzed. Many of them requested domestic OPU needles, ET catheters, culture media and ICSI pipettes under good quality control and quality assurance system. This trial may be contributed to industrialization and to global competence of Korean IVF-ET program. The results of this survey can be provide a fundamental base for development and production of domestic materials and consumables for human IVF-ET program.

• Proceedings of the KWS Conference
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• 1999.10a
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• pp.191-193
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• 1999