A heat treatment process for low-alloy structural steel and low-carbon structural steel

Abstract

The invention belongs to the technical field of heat treatment of iron and steel materials, and in particular relates to a heat treatment process of low-alloy structural steel and low-carbon structural steel. The process includes the following steps: put the material into the heating furnace, raise the temperature to 880°C-950°C with the furnace, normalize and keep it for 60-120 minutes; Cold, after air cooling, the temperature is controlled at 300°C-600°C; put the air-cooled material into the tempering furnace for tempering treatment, the tempering temperature is controlled at 450°C-650°C, keep warm for 120-180 minutes, and air-cool to room temperature. This process improves the toughness of low-alloy structural steel and low-carbon structural steel, refines the grain size, makes the yield (displacement) section of the material steel more than 2mm, and increases the yield strength by 15-20%, which can be used for bridge insulation Vibration materials or suitable for places that require high toughness of materials.

Description

technical field

[0001] The invention belongs to the technical field of heat treatment of iron and steel materials, and in particular relates to a heat treatment process of low-alloy structural steel and low-carbon structural steel. Background technique

[0002] The seismic isolation of bridges and buildings has become the main content of modern seismic isolation design, and the selection and treatment of seismic isolation materials have become the most core content. In particular, large bridges require large displacement changes and high requirements for shock absorption and isolation, and the requirements for shock absorption and isolation are extremely special. At present, some countries in the world have carried out systematic research on shock-absorbing and isolating materials, and have also achieved some results. However, most of them are used in the shock absorption and isolation of buildings, and the shock absorption effect is not obvious. The shock-absorbing and is...

Examples

Embodiment 1

[0030] Taking the low-alloy structural steel Q345B sample as an example, the composition (weight%) of the sample is: 0.18%C, 0.45%Si, 1.65%Mn, 0.03%P, 0.03%S, 0.01%N, 0.15%V , 0.25%Cr, 0.45%Ni, 0.20%Cu. The sample diameter d is 10mm, and the original gauge length Lo is 50mm.

[0031] After preparing the sample, set the process parameters of the heating furnace and tempering furnace: the normalizing temperature is 910°C, and the holding time is 90 minutes; the tempering temperature is 480°C, and the holding time is 120 minutes.

[0032] Then put the samples into the material frame, the samples are evenly arranged and the intervals are neat, put the material frame into the heating furnace, make sure the material frame is reliable, close the furnace door, call out the microcomputer process program, press "Start", the process will start automatically , and turn on the temperature recorder at the same time; after the heating and heat preservation program is over, close the normali...

Embodiment 2

[0041] Taking the low-carbon structural steel Q235 sample as an example, the composition (weight %) of the sample is: 0.20%C, 0.32%Si, 1.38%Mn, 0.043%P, 0.04%S, 0.006%N, 0.25%Cr , 0.28%Ni, 0.25%Cu. The sample diameter d is 10mm, and the original gauge length Lo is 50mm.

[0042] After preparing the sample, set the process parameters of the heating furnace and tempering furnace: the normalizing temperature is 920°C, and the holding time is 90 minutes; the tempering temperature is 650°C, and the holding time is 120 minutes.

[0043] Then put the samples into the material frame, the samples are evenly arranged and the intervals are neat, put the material frame into the normalizing furnace, make sure the material frame is reliable, close the furnace door, call out the microcomputer process program, press "Start", the process will start automatically , and turn on the temperature recorder at the same time; after the heating and heat preservation program is over, close the normaliz...

technical field

[0001] The invention belongs to the technical field of heat treatment of iron and steel materials, and in particular relates to a heat treatment process of low-alloy structural steel and low-carbon structural steel. Background technique

[0002] The seismic isolation of bridges and buildings has become the main content of modern seismic isolation design, and the selection and treatment of seismic isolation materials have become the most core content. In particular, large bridges require large displacement changes and high requirements for shock absorption and isolation, and the requirements for shock absorption and isolation are extremely special. At present, some countries in the world have carried out systematic research on shock-absorbing and isolating materials, and have also achieved some results. However, most of them are used in the shock absorption and isolation of buildings, and the shock absorption effect is not obvious. The shock-absorbing and is...

Examples

Embodiment 1

[0030] Taking the low-alloy structural steel Q345B sample as an example, the composition (weight%) of the sample is: 0.18%C, 0.45%Si, 1.65%Mn, 0.03%P, 0.03%S, 0.01%N, 0.15%V , 0.25%Cr, 0.45%Ni, 0.20%Cu. The sample diameter d is 10mm, and the original gauge length Lo is 50mm.

[0031] After preparing the sample, set the process parameters of the heating furnace and tempering furnace: the normalizing temperature is 910°C, and the holding time is 90 minutes; the tempering temperature is 480°C, and the holding time is 120 minutes.

[0032] Then put the samples into the material frame, the samples are evenly arranged and the intervals are neat, put the material frame into the heating furnace, make sure the material frame is reliable, close the furnace door, call out the microcomputer process program, press "Start", the process will start automatically , and turn on the temperature recorder at the same time; after the heating and heat preservation program is over, close the normali...

Embodiment 2

[0041] Taking the low-carbon structural steel Q235 sample as an example, the composition (weight %) of the sample is: 0.20%C, 0.32%Si, 1.38%Mn, 0.043%P, 0.04%S, 0.006%N, 0.25%Cr , 0.28%Ni, 0.25%Cu. The sample diameter d is 10mm, and the original gauge length Lo is 50mm.

[0042] After preparing the sample, set the process parameters of the heating furnace and tempering furnace: the normalizing temperature is 920°C, and the holding time is 90 minutes; the tempering temperature is 650°C, and the holding time is 120 minutes.

[0043] Then put the samples into the material frame, the samples are evenly arranged and the intervals are neat, put the material frame into the normalizing furnace, make sure the material frame is reliable, close the furnace door, call out the microcomputer process program, press "Start", the process will start automatically , and turn on the temperature recorder at the same time; after the heating and heat preservation program is over, close the normaliz...

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