Carbon steel foundry asks whether precision casting will have disadvantages?

　Carbon steel foundryAnalyze the common defects of precision casting with bubbles, which refers to the shortcomings of smooth holes in individual positions of precision castings. Air bubbles are usually discovered after machining. After many years of workshop production experience by technicians, the reasons and prevention methods of bubbles in precision casting are summarized as follows:
1. Reasons for the construction of carbon steel foundries:
(1) In most cases, bubbles appear mainly because the precision casting outer shell is not sufficiently roasted. When the molten steel is poured, a lot of gas occurs in the shell and cannot be discharged smoothly, thus invading into the molten metal to form bubbles;
(2) Because of the shell-making process or shell-shaped materials, the gas permeability of the shell is too poor, and the gas in the cavity is difficult to discharge, and enters the molten metal to form bubbles; 3. The air involved in the molten steel cannot be discharged during casting. Casting bubbles.
2. Prevention methods for carbon steel foundries:
(1) When the precision casting conditions permit, set up a row of bubbles at the highest point of the casting with complex structure.
(2) When designing the gating system, it is necessary to fully consider the exhaust requirements of the shell.
(3) The baking temperature and time of the shell should be reasonable, and the heat preservation time should be sufficient.
(4) The wax should be completely removed during dewaxing.
(5) Properly reduce the distance between the ladle nozzle and the sprue cup, and the pouring speed should be uniform to ensure that the steel fills the cavity stably, and the air in the molten steel is as little as possible so that the gas in the cavity and the molten steel can be discharged smoothly.

Carbon steel precision casting carbon steel is an iron-carbon alloy with a carbon content of 0.0218% to 2.11%. Also called carbon steel.

Generally, it also contains a small amount of silicon, manganese, sulfur, and phosphorus. Generally, the higher the carbon content of carbon steel, the greater the hardness and the higher the strength, but the lower the plasticity.

According to the quality of steel, carbon steel can be divided into ordinary carbon steel (higher phosphorus and sulfur), high-quality carbon steel (lower phosphorus and sulfur) and high-quality steel (lower phosphorus and sulfur) and special grade High-quality steel. According to the carbon content, carbon steel can be divided into low carbon steel (WC ≤ 0.25%), medium carbon steel (WC0.25%—0.6%) and high carbon steel (WC> 0.6%).

Generally used as engineering structure and ordinary mechanical parts. For example, Q235 can be used to make bolts, nuts, pins, hooks and less important mechanical parts, as well as rebar, section steel, and steel bars in building structures.

316 stainless steel is a kind of austenitic stainless steel. Due to the addition of Mo, its corrosion resistance and high temperature strength are greatly improved. The high temperature resistance can reach 1200-1300 degrees, and it can be used under harsh conditions. Carbon steel is no more corrosion resistant than 316 stainless steel.

Common steel grades and uses of carbon steel:

08F, carbon has low mass fraction, good plasticity and low strength, used for stamping parts such as automobile and instrument housing;

20. Good plasticity and weldability, used for parts with low strength requirements and carburized parts, such as hoods, welded containers, small shafts, nuts, washers, carburized gears, etc.;

45, 40Mn, good comprehensive mechanical properties after quenching and tempering, used for mechanical parts with greater stress, such as gears, connecting rods, machine tool spindles, etc.;