China factory hot selling black pipe,square/round /rectangular steel pipe
The square steel tube is iron carbon with a carbon content between 0.021% and 2.11%. In order to ensure its toughness and plasticity, the carbon content generally does not exceed 1.7%. In addition to iron and carbon, the main elements of steel are silicon, manganese, sulfur, phosphorus, etc. These metal elements play different roles.
Carbon can be said to exist in all steels. It is the most important hardening element in square steel tubes, which helps to increase the strength of steel. The use of chromium is to increase the wear resistance and hardness of square steel tubes. Manganese is also very important. The metal element helps to create a textured structure that adds ruggedness, strength, and wear resistance. During the rolling process, the interior of the steel is deoxidized and appears in most of the steel for cutting.
In addition, molybdenum is also present in the square steel tube, which can be used as a carbonizing agent to prevent the steel from becoming brittle. The strength of the steel is maintained at high temperatures, which occurs in many steels and air hardened steel, so that the square steel tube can be excellent. Performance is used in more situations.
Due to the high cutting power, the heat generated is high, and the thermal conductivity of the square steel tube is lower than that of the stainless steel, only 1/4 of the medium carbon steel, so the temperature in the cutting zone is high. When the cutting speed is less than 50 m/min, the cutting temperature is 200 ° C to 250 ° C higher than that of 45 steel, so the tool wear is severe and the durability is lowered.
In the past, the damper connecting rod was plated with the hard chrome process, and the corrosion resistance could not meet the requirements. Recently, the HEEF25 microcrack chrome plating process has been adopted, so that the thickness of the plating of the square steel pipe can reach 20±5μ, and the specification of 10l±3μ has a positive effect on ensuring the corrosion resistance and lubricity of the damper connecting rod.