630 Stainless Steel Rod Price Trend How much does it cost per square meter

630 Stainless Steel Rod Price Trend How much does it cost per square meter

Generally speaking, there are two main conditions for stainless steel rusting. One is that after cleaning and drying the stainless steel sample, there are patchy white spots on its surface. This phenomenon is quite common, accounting for about one-third of all experimental samples; Another situation is that stainless steel samples will flash black or reddish black rust lines or spots on their surface during immersion, and there will also be a certain amount of dark deposition in the immersion solution, and sometimes the immersion solution may even have color.

Fundamentally, stainless steel with white spots is qualified in terms of heavy metal policies. The formation of white spots may be due to the modification of the protective film on the surface of the stainless steel by acid solution, resulting in defects, pores, or salt formation on the surface of the stainless steel plate; Dark rust spots are iron oxides formed by severe corrosion of iron in stainless steel. The above two types of stains are generally difficult to remove, and even if sandpaper is used to remove them, they will regenerate after a period of time. The main cause of stainless steel rusting is usually due to the iron contained in the steel. However, as long as there is an oxide protective film on the surface of the stainless steel material, the iron will not be exposed to the air, and in this situation, stainless steel will not rust easily.

630 Stainless Steel Rod Price Trend How much does it cost per square meter

When it is not possible to place the entire stainless steel plate in the furnace for heat treatment (such as due to excessive product standards, peripheral welds in pipeline systems, or on-site equipment), then local post weld heat treatment is only feasible. Local post weld heat treatment requires careful planning to ensure controlled heating and cooling rates and achieve uniform and correct temperatures. Uneven and/or rapid heating can create harmful temperature gradients, leading to thermal stresses that cross the yield stress. This may cause new residual stresses to occur during the cooling of stainless steel plates.

Local post weld heat treatment can be carried out using high-speed gas burners, infrared burners, induction heating, and high or low resistance heating elements. Electrical equipment is simpler to install and operate than heating with natural gas or propane, especially on site. High voltage resistance heating is rarely used on site. Due to the need to place radiation heaters at a certain distance from the outside, and more importantly, the use of high voltage current may pose health and safety hazards. Low voltage resistance heating and induction heating are two commonly used methods.