Heavy Steel Rail Impact load

In general, the heavier the rail, the less the steel rail damage will be, and it is not easy to bend. Under this problem, there are two kinds of reinforcement.

1. The steel rail is alloying, its production process is simple, investment is low, energy consumption is low, the steel rail is strengthened overall, the surface hardness is even, the weldability is good.

2. Heat treatment of carbon steel, which can improve the strength and hardness of the rail, and good toughness and saving of alloy, suitable for mass production. Metallurgical industry production practice think: if you don't change the grade of steel, carbon steel heat treatment alone, it is difficult to greatly improve the strength. Only combining the micro alloying and heat treatment, the two complement each other, to both the higher strength can be obtained, and corresponding toughness, hardness and weldability of high quality steel.

These two methods can greatly reduce the former condition, the use of the rail will be more convenient. Heavy rail is a major part of the railway track, directly from the repetition and impact of locomotive wheel load, therefore, the requirements of rail steel have sufficient hardness, tensile strength, fatigue strength and toughness. Due to the rapid development of railway line without expansion joints, it should also have certain welding property. The track occurred in 1767, when the material used was malleable iron. In 1830, the British, C.V ignoles and r. l.s. tevens, designed an inverted t-shaped steel rail, which was successfully rolled in England in 1857. In 1865, the United States rolled out the Bessemer rail. At present, the world's annual production of steel rail is about 10 million tons. The countries with the most output are the Soviet union, the United States and China.

Rail are normally according to the tensile strength of three levels, that is, the standard rail (tensile strength of 70 ~ 70 KGF / / mm), wear-resisting level the rail (tensile strength of 90 ~ 90 KGF / / mm) and special rail (tensile strength of 110 ~ 110 KGF / / mm). The chemical composition, strength and elongation of the steel rail steel must meet the requirements of the standard, in addition, the inspection of falling hammer, metallographic, low-power, hardness test and surface quality and dimensional deviation shall be carried out. The earliest steel rail in the world was made of carbon steel with carbon content of 0.3 ~ 0.4%. Currently, carbon steel is still being used in a large number of countries, but the carbon content of steel is gradually increased by the amount of carbon (C. 0.5 ~ 0.8%). In some steel, manganese content also increased (Mn0.6 ~ 1.0%). The standard components in China's heavy rail steel: C / 0.67 ~ 0.80%, Si - 0.13 ~ 0.28%, Mn0.7 ~ 1.0%, P 0.04% or less, S 0.05% or less, as the locomotive axle load, driving speed and the increase of the volume, weight per unit length in improving rail, alloy steel, improving steel production process and product quality has been making progress.

When loading and unloading the rails, the staff should be equipped with the personnel. One head or one first must not be slammed. Heavier rail should be shouldered and shouldered.