A kind of production method of low hardness 20crmnti round steel

Abstract

The embodiment of the present invention provides a production method of low-hardness 20CrMnTi round steel, which is characterized in that it includes: designing and controlling the composition of the round steel billet as carbon: 0.18%-0.22%, silicon: 0.20%-0.30%, manganese: 0.85% %~1.05%, Chromium: 1.05%~1.25%, Titanium: 0.050%~0.070%, Aluminum: 0.020%~0.040%, Oxygen≤0.0020%. RH vacuum treatment, continuous casting into continuous casting slabs; continuous casting slabs are heated in three stages in the furnace, and after heating, they are rolled into rolled round bars by rough, medium and finish rolling units; rolled round bars pass through water piercers Carry out controlled cooling; after rolling, the round steel passes through water and enters the cooling bed for natural cooling, and the temperature of the upper cooling bed of the round steel is controlled at 930±30°C.

Description

technical field [0001] The invention belongs to the field of metallurgy, and in particular relates to a production method of low-hardness 20CrMnTi round steel. Background technique [0002] In recent years, my country's automobile, construction machinery and other industries have developed vigorously, and the domestic demand for 20CrMnTi series round steel is very strong. According to the statistics of China Association of Automobile Manufacturers and China Gear Professional Association, China's automobile production and sales will reach 28 million in 2019, and the consumption of automobile gear steel will be about 3.7 million tons. China's automobile production will grow at an average annual rate of about 10%. , analyzing the product composition of the automotive industry in recent years, it can be found that the fastest growing vehicles in the automotive industry are mainly heavy-duty trucks and cars. The most important consumer of gear steel. [0003] Gear steel has a w...

AI Technical Summary

Problems solved by technology

[0006] The use process of 20CrMnTi round steel at the user's place is generally: round steel → shearing or sawing blanking → heating → stamping → heat treatment, the first process in the user's use process is to cut according to the blanking size required by different workpieces Or sawing blanking, therefore, for the 20CrMnTi round steel with high hardness, defects such as chipping (or "lack of meat") will be caused during blanking, and such blanking parts cannot be subsequently stamped and formed, resulting in waste products. In addition, high-hardness round steel increases machine loss

[0009] In view of the high hardness of small-sized 20CrMnTi round steel, the production process has been optimized and improved, such as reducing the content of C, Mn, Cr and other elements within the standard range, and quickly sending it to the warehouse through the cooling bed for stack cooling and slow cooling after final rolling , but the improvement effect is not ideal