High toughness ring chain steel for mine and method for producing the same

Abstract

The invention discloses a high strength and toughness steel used for a ring chain, wherein, the chemical elementary compositions based on weight percentage are as follows: C: 0.20 to 0.26 percent, Mn: 1.10 to 1.40 percent, Ni: 0.85 to 1.15 percent, Cr: 0.40 to 0.60 percent, Mo: 0.40 to 0.60 percent, V: 0.03 to 0.10 percent, Al: 0.020 to 0.050 percent, Si: less than or equal to 0.25 percent, Cu: less than or equal to 0.25 percent, S: less than or equal to 0.020 percent, P: less than or equal to 0.020percent, and Fe and inevitable impurity as the rest. According to general arc melting, refining technology and given alloy elements ratio, the invention uses continuous casting techniques to produce casting billets. The average casting temperature is 1150 to 1200 DEG C, beginning temperature of rolling is 1130 to 1180 DEG C, and final temperature of rolling is 760 to 800 DEG C; after being rolled, the billets are cooled in water and air; Then the hot rolled steel bars are annealed at 680 to 710 DEG C for 8 to 12 hours, and the tapping temperature is less than or equal to 250 DEG C, and then cooled in air, and wind is avoided. Therefore, the high strength and toughness ring chain steel forms into spherical pearlite, and has high cleanliness, uniform and fine structure, uniform and moderate hardness and excellent comprehensive mechanical properties after heat treatment.

Description

technical field [0001] The invention relates to the compositional design and manufacturing method of structural steel in the metallurgical industry, in particular to the compositional design and manufacturing method of high-strength and high-toughness mining round link chain steel. Background technique [0002] Coal is the main part of my country's energy composition, and underground coal mining occupies a large proportion of my country's coal production. As the transmission chain on the scraper conveyor and various coal plows - the circular link chain is the key and vulnerable part of these equipment. According to national standards, round link chains are divided into three levels: B, C and D. Class B round link chains are mainly used in occasions where the load is small and not important, and the raw materials are usually low-carbon alloy steel, such as: 20MnSi and 23MnSiV. Class D round link chains require high strength (tensile strength Rm ≥ 1470Mpa), and strict requir...

AI Technical Summary

Problems solved by technology

[0008] The technical problem to be solved by the present invention is to provide a C-grade steel for mining circular chains, which solves the problems of uneven microstructure, low strength and plasticity, and poor matching between strong and plastic in the prior art. Fatigue life failure, etc.

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