Investigation of Effects of Mig Welding on Corrosion Behaviour of AISI 1010 Carbon Steel
This paper presents the corrosion behaviour of welded low carbon steel at different welding voltages and filler materials. The welding process was conducted on butt joint 
specimens using the metal inert gas (MIG) technique at a welding voltage range of 19 to 21 V with 1 V interval, and the filler materials used were ER 308L and ER 70S-6 with 
1.2 mm diameter. Heat treatment through full annealing was done to the welded low carbon steel, and the corrosion behaviour was tested using a synthetic seawater 
environment with 3.5 wt% NaCl. Microstructure changes were observed using a scanning electron microscope (SEM). The results showed that the corrosion rate decreased when the welding voltage increased, as it directly affected the welding heat input. The welding heat input was found to have a significant effect on the corrosion rate as it changed the ferrite content in the microstructure of the specimens. Decrease in the corrosion rate was also found when the full annealing process was done to the 
specimens and ER 308L filler material was used. From a metallographic study, iron oxides and pitting were found on the surface of the exposed area after the corrosion test. 
It is apparent that the combination of higher welding voltage, heat treatment and the use of ER 308L filler material can reduce the corrosion rate of AISI 1010 carbon steel.
Stress corrosion damage on austenitic stainless steel in sodium chloride
The aim of this work is to present the corrosion damage mechanism of austenitic stainless steel 304. The C-ring specimens are chosen according to ASTM G-38 to resemble the stress conditions during the applied load. The specimens are immersed in 3.5% wt of NaCl solution. The variable conditions were studied at a fixed stress of 379Mpa and immersions for 720 hours. The stress distribution over the surface of specimens is formulated by means of a finite-element analysis. The result of the finite-element analysis shows that the region that was perpendicular to the shift in the direction of the pressure was subjected to the highest load. Using the potentiodynamic polarisation measurement method and microscopic observation, the corrosion polarisation behaviour of austenitic stainless steel became more active in cases when immersion and stress are applied simultaneously. The stress on the surface of the specimen shows a significant effect on the polarisation mechanism in the analysed area. The result also shows that the locations of pitting corrosion are apparent on the highest stress area. There is useful information to analyse the corrosion behaviour especially for applications under mechanical loading in corrosive environments, it drives the corrosion behaviour to the critical condition.
A New Vacuum Pressure Infiltration CFRP Method and Preparation Experimental Study of Composite
In order to prepare a carbon-fiber-reinforced polymer composite (CFRP) with ideal microstructure and properties, a new vacuum pressure infiltration CFRP method is proposed based on an analysis of existing CFRP preparation process methods. Research on composite material preparation systems was carried out by using this new method principle. The system mainly includes a fiber pre-forming module, a vacuum heating infiltration module, a hot-press curing molding module, and a data acquisition control module. Under the conditions of natural curing at 0 MPa + 6 h + 25 °C, vacuum heating curing at –0.05 MPa + 30 min + 80 °C, and hot-press curing at 0.7 MPa + 5 min + 50 °C, a two-dimensional (2D) CFRP with excellent microstructure and properties was successfully prepared. Observing the microstructure of the prepared composite material, it can be found that the inside of the composite material was sufficiently and uniformly infiltrated, and common preparation defects such as holes and delamination were effectively controlled. Through the performance test, the bending strength of the material reached 790 MPa.