Testing of Welding Electrodes for Diffusible Hydrogen and Coating Moisture

Specimens of various sizes are used to determine hydrogen content in deposited metals in such standards as ISO 3690, AWS A 4.3, and GOST 23338 while measuring methods are the same. It causes problems in comparison of experimental results and brings up the following question: what kind of specimen size is optimal to determine hydrogen content? An optimal specimen size was estimated using a calculation method. Experimental and calculation results obtained by using specimens with estimated dimensions were compared to the results obtained by using the specimen with dimensions of 100*25*8 mm to determine hydrogen content in a deposited metal.

Download Full-text

Coating of Electrode by Myristic Acid via Microwave Reaction

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.306-307.544 ◽

2011 ◽

Vol 306-307 ◽

pp. 544-547

Author(s):

Wen Jun Chen ◽

Chi Bin Gui ◽

Ji Sun

Keyword(s):

Petroleum Ether ◽

Electrode Surface ◽

Myristic Acid ◽

Microwave Oven ◽

Light Petroleum ◽

Absorption Property ◽

Diffusible Hydrogen ◽

Deposited Metal ◽

Microwave Reaction ◽

Ft Ir

Electrodes can absorb moisture easily so that the diffusible hydrogen is quite high in the weld bead. Fe3O4 powder is used to promote the reaction of myristic acid and the electrode surface, and reduce the diffusible hydrogen, because of its excellent microwave absorption property. Electrodes are immersed to the light petroleum solution which contains myristic and Fe3O4 particles, then they are put into the microwave oven and become water-resistant . The results of FT-IR and SEM microscope indicate that Fe3O4 powder absorb microwave and melt myristic acid to form the water-resistant film. The best ratio of myristic acid in the petroleum ether is 18% and the diffusible hydrogen of the deposited metal of microwave treated electrode decreased to 83% of the untreated electrode.

Download Full-text

Research Regarding Wear Protection in Sever Exploitation Condition of Crusher Jaws

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.1128.390 ◽

2015 ◽

Vol 1128 ◽

pp. 390-393

Author(s):

Daniel Tihanov Tanasache ◽

Emilia Binchiciu ◽

Carmen Florea ◽

Victor Geanta ◽

Horia Binchiciu

Keyword(s):

High Pressure ◽

Active Surface ◽

Protection System ◽

Innovative Technology ◽

Diffusible Hydrogen ◽

Wear Area ◽

Base Materials ◽

Wear Protection ◽

Self Protection ◽

Fall Deposits

The paper presents a new innovative technology that is experimented to protect from wear crusher jaws that grind basalt aggregates. These are subjected, in exploitation, at the active surface level, to complex requests of wear at abrasion under high pressure combined with fatigue at high efforts. Actual developed stage in casted form from hardened steels present the disadvantage of being sensitive to excavation, pitting type, wear, in hard areas or in those with segregation at the crystalline grain limit. Fighting the above mentioned phenomena’s if accomplished by loading through welding on the jaws active surfaces layers with proper proprieties to obtain intelligent self-protection to wear systems. The thickness of the deposits is determined experimental based on minimizing the tensions on the base metal. The position and geometry of the wear self-protection system were established on data collected from crusher jaws used in exploitation, in Bata quarry, Romania. The morphology of the wear self-protection system layers is developed depending on the type of wear it will encounter during exploitation. Thus in the central impact and wear area, under abrasion and high pressure, depositing the self-protection at wear system consists of alternative rows of tough, hardened, with small grain size materials; in the side areas, subjected to the constant grinded material fall, deposits developed with tough materials. To assure the manufacturing process for the new products, at Sudotim AS Timișoara, we experimentally adapted rods SUDODUR CWTV and SUDINOX CN according to quality-price conditioned imposed as well as its lifespan in exploitation. Requests followed optimizing the product based on minimum price, minimum alloying level and low level of diffusible hydrogen and high purity of base materials.

Download Full-text