Low-cost and high-strength stainless steel and manufacturing method of welding pipe thereof

Abstract

Provided are low-cost and high-strength stainless steel and a manufacturing method of a welding pipe of the low-cost and high-strength stainless steel. The high-strength stainless steel is prepared from, by weight percent, 0.02%-0.15% of C, not larger than 0.6% of Si, 2%-15% of Mn, 12%-20% of Cr, 0.5%-7.0% of Ni, not larger than 0.04% of P, not larger than 0.03% of S, 0.02%-0.20% of N, 0.5%-2.0% of Cu, 0.001%-0.08% of AL, 0.001%-0.10% of V and the balance Fe and inevitable impurities, and the total quantity of the impurities does not exceed 0.05%. Meanwhile, the formula 12.5<=100*(0.5*Mn+Ni+30*N)<=22 needs to be met. The tensile strength of the high-strength stainless steel ranges from 700 MPa to 1,800 MPa, the yield strength of the high-strength stainless steel ranges from 400 MPa to 1,200 MPa, and the ductility of the high-strength stainless steel ranges from 50% to 12%. The requirements for car weight reduction, high safety performance, good corrosion resistance and the like are met, and a part and other products manufactured through the welding pipe have delaying and cracking resisting capacity.

Description

technical field [0001] The invention relates to the manufacture of austenitic stainless steel plates and steel pipes, in particular to a method for manufacturing low-cost high-strength stainless steel and its welded pipes. Background technique [0002] With the continuous improvement of environmental protection requirements for automobiles, lightweight has become the development direction of automobile materials. At the same time, low life cycle cost inventions are also an important basis for material design in the automotive industry. For this reason, first of all, more and more high-strength steels are used in automobile parts to realize the weight reduction of automobiles. [0003] At present, carbon steel and high-strength steel have been widely used in the automotive industry. Especially in the new energy vehicle industry, foreign car companies have shifted the design of materials from the conventional single-cost invention to the design of the full life cycle cost ba...

AI Technical Summary

Problems solved by technology

[0011] The first two patents in the above four patents provide two kinds of high-strength austenitic stainless steel, but the composition does not contain Mo, Nb, Ti and other elements that improve corrosion resistance. It is difficult to meet the requirements of corrosion resistance under the conditions

The third patent contains alloying elements such as Nb, Ti, and Ce. Nb and Ti can improve corrosion resistance and welding performance. Adding rare earth Ce can also improve mechanical properties, but its own addition process is relatively complicated and the yield is not high. , increasing alloy cost

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