Alloy steel, seamless steel pipe and heat treatment technology of shaped steel pipe

Abstract

The invention discloses alloy steel with high tensile strength and yield strength, high hardness, low thermal expansion coefficient, good corrosion resistance, oxidation resistance and weldability. The alloy steel contains the following components of: by weight, 0.12-0.17% of carbon, 0.25-0.40% of silicon, 1.2-1.39% of manganese, 0.02-0.04% of niobium, 0.04-0.06% of vanadium, 0.02-0.04% of titanium, 0.02-0.04% of aluminium, 0.0005-0.0035% of boron, chromium being less than or equal to 0.1%, nickel being less than or equal to 0.05%, copper being less than or equal to 0.05%, phosphor being lessthan or equal to 0.025%, sulfur being less than or equal to 0.025%, and the balance being iron. The invention also discloses a seamless steel pipe prepared by the alloy steel and a heat treatment technology of a shaped steel pipe molded based on the seamless steel pipe. The technology is to successively carry out step heating quenching treatment and temper heat treatment on the molded shaped steel pipe. The alloy steel provided by the invention and the shaped steel pipe obtained by the alloy steel and the heat treatment technology are mainly used in fire-fighting equipment.

Description

technical field [0001] The invention relates to metal rolling processing and metal material heat treatment technology, in particular to alloy steel, alloy steel pipe and heat treatment technology. Background technique [0002] Firefighting equipment belongs to the fire safety industry. It is an important facility to protect buildings, people's property, fire safety and personnel life safety. It is an important part of modern buildings and a strong guarantee for fire rescue. In a complex environment, fire-fighting equipment needs to have the characteristics of high strength, temperature difference resistance, long service life and excellent comprehensive performance. However, the materials currently used to manufacture fire-fighting equipment have low strength, limited toughness, and low comprehensive performance, resulting in small load-bearing capacity, poor earthquake resistance, and low bending and twisting resistance of fire-fighting equipment. big. Therefore, the long...

AI Technical Summary

Problems solved by technology

[0011] 1. The tensile strength, yield strength and hardness of metal materials are low, which cannot meet the requirements of fire-fighting equipment with good bending strength, twist resistance, large bearing capacity and strong earthquake resistance.

[0012] 2. Metal materials have high thermal expansion coefficient, strong temperature difference sensitivity, poor high temperature corrosion resistance and oxidation resistance, and cannot adapt to large temperature difference changes and complex and harsh rescue environments

[0013] 3. The poor welding performance of metal materials makes it difficult to manufacture fire-fighting equipment, especially the unstable safety and reliability

This process can make the material have a certain tensile strength and yield strength, but the material has insufficient toughness, low bending and twisting resistance, especially the strong temperature difference sensitivity, which is a great disadvantage and limitation for fire-fighting equipment.

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