Ishlab chiqish

INTRODUCTION
Nowadays, the shafts used in the stamping plants of manufacturing enterprises are the main and very expensive part of the machines for the production of rolled products. They are exposed to various stresses and strains during operation. In addition, the geometric dimensions and material of the shafts must ensure that they can withstand the heaviest loads that occur during the shift sequence. Another important factor related to the service life of the shafts is the corrosion resistance of its material. Shaft details are being made from high – strength, low – alloyed steels. These steels have better mechanical properties and corrosion resistance than ordinary structural carbon steels. Because they are designed to respond not to chemical composition, but to unique mechanical properties. High – strength low – alloyed steels have a low carbon content (0.05 – 0.25% C), and the manganese content is up to 2.0%. It contains a small amount of elements such as chromium, nickel, molybdenum, copper, nitrogen, vanadium, niobium, titanium and zirconium. For many low – alloyed steels, the main task of alloying elements is to optimize mechanical properties and hardness after heat treatment [1 – 3].
Shafts made of 35XGCL and 35XGCA steel are used for ball rolling machines in the “1st grade rolling” plant of “UzMetkombinat” JSC, one of the leading enterprises of our republic. This 35XGCL brand steel is cast in the “Casting Mechanics” plant of the combine.
MAIN PART
Today, in the casting-mechanics plant of JSC “UzMetkombinat”, problems during the casting of shafts made of 35XGCL steel for ball rolling machines into sand – clay molds and their causes were analyzed (Pic. 1. 2.).

Pic. 1. Effect of non – metallic inclusions and porosity on alloy quality (after machining)

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