Plate lamination defect is one of the primary processing discontinuity that originates during hot or cold forming processes and is considered as a serious metal plate defect. All the metals contain discontinuities at micro and macro levels. These discontinuities, when above the acceptance level, are termed as defects. The discontinuities in metal are classified according to the stage of manufacturing in which they initiate. Plate lamination defect can be defined as flat and thin subsurface separations present inside metal plate, parallel to the surface of the plates. The sources of this defect are inherent discontinuities present in metal such as inclusion and porosity, which are flattened during the rolling process. Carbon Steel Plate Lamination Defect & Reasons A carbon steel plate is produced by the process of hot or cold rolling a thick slab. During this process, carbon steel may pass through the rollers many times to achieve the desired thickness. Each pass results in
Comparison of the use of rutile and cellulosic electrodes Types of electrodes and their compositions Many types of manual metal arc (MMA) electrodes are available on the market. Depending on the main constituent of their flux, they are grouped into three categories: cellulosic, rutile and basic. All electrodes consist of a cored wire (typically 2.5–6mm diameter) coated by a flux. The core wire is generally made of low-quality riming steel and the fluxes contain many elements allowing refinement of the weld macrostructure. The composition of the flux impacts the electrodes’ behaviour. The main constituents of the different types of electrodes and the shielding gas created for each are described in Table 1 (Bowniszewski, 1979). Table 1 Main constituent of the three possible types of electrodes and shielding gas created by its combustion. Electrode type Main constituent Shielding gas created Rutile Titania (TiO2) Mainly CO2 Basic Calcium compounds Mainly CO2 Cellulosic
Now a days we came across h earing plenty of NDT training centres are offering NDT level 2 in Basic NDT methods like RT, UT, MT, PT etc within a duration of 15 days on 2- 4 hours training session per day. We are posting this article here for making aware the general public about the facts on what's NDT and How can be it acquired. Does'nt matter which training centre major factor shall be is there worth for what you pay and will it be recognized in industry and also will it be useful for the certified person because it's your hard earned Money is paying for each and every training program Normal NDT programs offered by Institutions are based on ASNT SNT 1A practice standard and which are accepted world wide if it's properly delivered. As per ASNT published minimum training requirement each individual candidate should get a Minimum training hours for practical and theory for each method Eg: Ultraosonic Testing direct level 2 requires a Minimum Training hours of 120 f