A kind of manufacturing method of silicon-containing stainless steel seamless pipe

Abstract

The invention discloses a manufacturing method for a silicon-containing stainless steel seamless tube. The method comprises the following procedures: heating of a tube blank; perforating; cold rolling; heat treatment; straightening; and pickling. In the procedure of heat treatment, a short-time high-temperature heat treatment process is employed, heat treatment temperature is 1090 to 1110 DEG C, a heat preservation coefficient is 0.8 to 1.5 min / mm, and heat preservation time is determined according to steel tube thickness and is calculated by multiplying the heat preservation coefficient with the steel tube thickness; and in the procedure of straightening, a forward-backward bidirectional straightening method is employed, backward straightening is carried out after original unidirectional straightening, so the effect of integral fragmentation of a surface oxide skin is realized. According to the invention, the short-time high-temperature heat treatment process is employed, so the surface oxide skin becomes thinner and loose after heat treatment, which facilitates easy removal of the oxide skin during pickling; the forward-backward bidirectional straightening method is employed for integral fragmentation of the surface oxide skin, so the oxide skin left in pickling is eliminated, a better fragmentation effect is exerted on the loose oxide skin, and product surface quality after pickling is further guaranteed.

Description

technical field

[0001] The invention relates to a method for manufacturing an austenitic heat-resistant stainless steel seamless pipe in the metallurgical industry, in particular to a method for controlling the surface quality of the cold-worked surface of silicon-containing stainless steel 16Cr25Ni20Si2. Background technique

[0002] Conventional stainless steel is generally austenitic Cr-Ni stainless steel. Si element in this type of steel is used as an impurity element, and the Si content is generally required to be controlled at ≤1.0%. For silicon-containing austenitic stainless steel 16Cr25Ni20Si2, Si is added as a beneficial element (the content of Cr and Ni needs to be adjusted), and the Si content is required to be controlled at 1.5-2.5%.

[0003] Silicon-containing stainless steel 16Cr25Ni20Si2 is an austenitic heat-resistant stainless steel with excellent oxidation resistance. It is widely used in the manufacture of various heat-resistant components of heating fur...

Examples

Embodiment 1

[0046] Example 1 (Steel pipe representative specification φ38×3mm)

[0047] 1. Tube billet heating—piercing → cold rolling → (short-time high temperature) heat treatment → (both positive and negative) straightening → pickling.

[0048] 2. Heat treatment in a roller hearth heat treatment furnace with a temperature of 1090°C, a heat preservation coefficient of 1.0min / mm, and a heat preservation time of 1.0min / mm×3mm=3.0min. Pickling, the surface has no pitting and residual scale, and the mechanical properties of the finished product are qualified. (See Table 4 below)

[0049] 3. Steel pipe heating, piercing and other processes are conventional steel pipe processes, the implementation process is smooth, the mechanical properties of the finished product are qualified, the surface quality is good, and there is no impact on environmental protection and safety.

Embodiment 2

[0050] Embodiment 2 (steel pipe represents finished product specification 38 * 3mm)

[0051] 1. Tube billet heating—piercing → cold rolling → (short-time high temperature) heat treatment → (both positive and negative) straightening → pickling.

[0052] 2. Heat treatment in a roller hearth heat treatment furnace, the temperature is 1100°C, the heat preservation coefficient is 1.2min / mm, and the heat preservation time is 1.2min / mm×3mm=3.6min. Pickling, the surface has no pitting and residual scale, and the mechanical properties of the finished product are qualified. (See Table 4 below)

[0053] 3. Steel pipe heating, piercing and other processes are conventional steel pipe processes, the implementation process is smooth, the mechanical properties of the finished product are qualified, the surface quality is good, and there is no impact on environmental protection and safety.

Embodiment 3

[0054] Embodiment 3 (steel pipe represents finished product specification 38 * 3mm)

[0055] 1. Tube billet heating—piercing → cold rolling → (short-time high temperature) heat treatment → (both positive and negative) straightening → pickling.

[0056] 2. Heat treatment in a roller hearth heat treatment furnace, the temperature is 1110°C, the heat preservation coefficient is 1.3min / mm, and the heat preservation time is 1.3min / mm×3mm=3.9min. Pickling, the surface has no pitting and residual scale, and the mechanical properties of the finished product are qualified. (See Table 4 below)

[0057] 3. Steel pipe heating, piercing and other processes are conventional steel pipe processes, the implementation process is smooth, the mechanical properties of the finished product are qualified, the surface quality is good, and there is no impact on environmental protection and safety.

technical field

[0001] The invention relates to a method for manufacturing an austenitic heat-resistant stainless steel seamless pipe in the metallurgical industry, in particular to a method for controlling the surface quality of the cold-worked surface of silicon-containing stainless steel 16Cr25Ni20Si2. Background technique

[0002] Conventional stainless steel is generally austenitic Cr-Ni stainless steel. Si element in this type of steel is used as an impurity element, and the Si content is generally required to be controlled at ≤1.0%. For silicon-containing austenitic stainless steel 16Cr25Ni20Si2, Si is added as a beneficial element (the content of Cr and Ni needs to be adjusted), and the Si content is required to be controlled at 1.5-2.5%.

[0003] Silicon-containing stainless steel 16Cr25Ni20Si2 is an austenitic heat-resistant stainless steel with excellent oxidation resistance. It is widely used in the manufacture of various heat-resistant components of heating fur...

Examples

Embodiment 1

[0046] Example 1 (Steel pipe representative specification φ38×3mm)

[0047] 1. Tube billet heating—piercing → cold rolling → (short-time high temperature) heat treatment → (both positive and negative) straightening → pickling.

[0048] 2. Heat treatment in a roller hearth heat treatment furnace with a temperature of 1090°C, a heat preservation coefficient of 1.0min / mm, and a heat preservation time of 1.0min / mm×3mm=3.0min. Pickling, the surface has no pitting and residual scale, and the mechanical properties of the finished product are qualified. (See Table 4 below)

[0049] 3. Steel pipe heating, piercing and other processes are conventional steel pipe processes, the implementation process is smooth, the mechanical properties of the finished product are qualified, the surface quality is good, and there is no impact on environmental protection and safety.

Embodiment 2

[0050] Embodiment 2 (steel pipe represents finished product specification 38 * 3mm)

[0051] 1. Tube billet heating—piercing → cold rolling → (short-time high temperature) heat treatment → (both positive and negative) straightening → pickling.

[0052] 2. Heat treatment in a roller hearth heat treatment furnace, the temperature is 1100°C, the heat preservation coefficient is 1.2min / mm, and the heat preservation time is 1.2min / mm×3mm=3.6min. Pickling, the surface has no pitting and residual scale, and the mechanical properties of the finished product are qualified. (See Table 4 below)

[0053] 3. Steel pipe heating, piercing and other processes are conventional steel pipe processes, the implementation process is smooth, the mechanical properties of the finished product are qualified, the surface quality is good, and there is no impact on environmental protection and safety.

Embodiment 3

[0054] Embodiment 3 (steel pipe represents finished product specification 38 * 3mm)

[0055] 1. Tube billet heating—piercing → cold rolling → (short-time high temperature) heat treatment → (both positive and negative) straightening → pickling.

[0056] 2. Heat treatment in a roller hearth heat treatment furnace, the temperature is 1110°C, the heat preservation coefficient is 1.3min / mm, and the heat preservation time is 1.3min / mm×3mm=3.9min. Pickling, the surface has no pitting and residual scale, and the mechanical properties of the finished product are qualified. (See Table 4 below)

[0057] 3. Steel pipe heating, piercing and other processes are conventional steel pipe processes, the implementation process is smooth, the mechanical properties of the finished product are qualified, the surface quality is good, and there is no impact on environmental protection and safety.

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