Low-cost non-quenched and tempered high-strength weathering steel with yield strength level of 700MPa and manufacturing method thereof

Abstract

The invention provides low-cost non-quenched and tempered high-strength weathering steel with yield strength level of 700MPa for containers and a manufacturing method thereof. Based on the carbon manganese structural steel composition, the reinforcement effect is enhanced by adding a proper amount of micro-alloy elements such as Nb, Ti, Cu, Cr, Ni and the like, adopting a controlled rolling and controlled cooling technique, taking production characteristics of a normal hot continuous rolling machine into consideration and using a high-Ti component design. Meanwhile, Si content is reduced and high cold forming performance is ensured. The weathering steel for the containers comprises the following components in percentage by weight: 0.05 to 0.10 percent of C, less than or equal to 0.15 percent of Si, 1.5 to 2.0 percent of Mn, less than or equal to 0.015 percent of P, less than or equal to 0.01 percent of S, 0.3 to 0.8 percent o Cr, 0.2 to 0.4 percent of Cu, 0.15 to 0.4 percent of Ni, 0.09 to 0.15 percent of Ti, 0.02 to 0.08 percent of Nb, less than or equal to 0.005 percent of N, less than or equal to 0.002 percent of O and the balance of Fe and inevitable impurities. The yield strength is over 700MPa, the tensile strength is over 800MPa and the elongation is over 18 percent.

Description

technical field [0001] The invention relates to a low-cost manufacturing method of non-quenched and tempered high-strength weathering steel with a yield strength of 700 MPa, belonging to the technical field of hot-rolled high-strength steel production. Background technique [0002] At present, the use of containers for long-distance transportation accounts for a large proportion, and some of them are used in severe cold regions such as North America and Northern Europe, and the use environment is very harsh. Due to local corrosion, there are many cases where it cannot withstand long-term use. The requirements for the use of containers are light weight, long life and weather resistance, so the requirements for manufacturing materials are to have both high strength and certain weather resistance. [0003] In this regard, many patents involve the manufacture of high-strength weather-resistant steel plates, and the methods of microalloying are different. [0004] The inventor ...

AI Technical Summary

Problems solved by technology

At present, the production of 700MPa steel at home and abroad not only increases the cost of steel, but also increases the difficulty of recycling steel later, especially rare elements, such as frequently added Mo, etc.

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