B-stage acid-resistant pipeline steel plate and rolling process thereof

Abstract

The invention discloses a B-stage acid-resistant pipeline steel plate and a rolling process thereof. The B-stage acid-resistant pipeline steel plate is prepared from the following chemical componentsin percentage by mass: 0.010%-0.040% of C, 0.10%-0.30% of Si, 0.80%-0.90% of Mn, less than or equal to 0.015% of P, less than or equal to 0.0010% of S, 0.10%-0.20% of Ni, 0.10%-0.20% of Cu, 0.020%-0.040% of Nb, 0.08%-0.15% of Mo, 0.010%-0.020% of Ti, 0.001%-0.003% of Ca, 0.010%-0.040% of Al and the balance of Fe and inevitable impurities, wherein Ceq is 0.16-0.23%, and Pcm is 0.07-0.13%. The B-stage acid-resistant pipeline steel plate adopts a low-temperature austenitizing process to effectively refine structure crystalline grains, improves adverse effect of a belt-shaped structure, and meetsacid and corrosion resistance of products.

Description

technical field

[0001] The invention relates to the technical field of iron and steel smelting, in particular to a B-grade acid-resistant pipeline steel plate and a rolling process. Background technique

[0002] Due to the over-saturation of the steel market, the competitiveness of enterprises is becoming increasingly fierce, and the gross profit of conventional varieties is getting lower and lower. The development of high-grade products has become the key to the survival and development of enterprises. The demand for pipeline steel products in the international market is quite large. Due to the difficulty in production and the strict requirements on product quality, few companies have the qualifications to supply pipelines. For B-level acid-resistant export pipelines, Nb has always been used for tax rebates. Nb has a great effect on product microalloying and can refine the microstructure Granularity, anti-acid performance has no side effects, but the cost is higher. Conte...

Examples

Embodiment 1

[0032] A grade B acid-resistant pipeline steel plate provided in this example has the following chemical composition and mass percentage: C: 0.010%-0.017%, Si: 0.10%-0.20%, Mn: 0.80%-0.89%, P≤0.012% , S≤0.0008%, Ni: 0.10%~0.18%, Cu: 0.10%~0.15%, Nb: 0.03%~0.040%, Mo: 0.10%~0.15%, Ti: 0.01%~0.016%, Ca: 0.001% ~0.002%, Al: 0.010%~0.036%, the balance is Fe and unavoidable impurities, Ceq: 0.16~0.23%, Pcm: 0.07~0.13%.

[0033] The rolling process of the grade B acid-resistant pipeline steel plate includes the following steps:

[0034] S1. After surface inspection, the blank is sent to a walking heating furnace for heating. The austenitizing temperature is 1100-1110°C. The heating time is 9.6-11min / cm calculated based on the thickness of the billet, and the soaking time is more than 40min;

[0035] S2. The starting temperature of rough rolling is set at 1073°C, the finishing temperature of rough rolling is 985°C, the reduction rate of the penultimate pass of rough rolling is more ...

Embodiment 2

[0040] A grade B acid-resistant pipeline steel plate provided in this example differs from Example 1 in that its chemical composition and mass percentage are as follows: C: 0.020%-0.030%, Si: 0.20%-0.30%, Mn: 0.80% ~0.90%, P≤0.015%, S≤0.0010%, Ni: 0.15%~0.20%, Cu: 0.15%~0.20%, Nb: 0.025%~0.035%, Mo: 0.08%~0.13%, Ti: 0.01% ~0.02%, Ca: 0.001%~0.003%, Al: 0.02%~0.04%, the balance is Fe and unavoidable impurities, Ceq: 0.16~0.23%, Pcm: 0.07~0.13%.

Embodiment 3

[0042] A grade B acid-resistant pipeline steel plate provided in this example differs from Example 1 in that its chemical composition and mass percentage are as follows: C: 0.030%-0.040%, Si: 0.15%-0.25%, Mn: 0.80% ~0.90%, P≤0.015%, S≤0.0010%, Ni: 0.10%~0.15%, Cu: 0.10%~0.15%, Nb: 0.020%~0.030%, Mo: 0.10%~0.15%, Ti: 0.01% ~0.02%, Ca: 0.001%~0.003%, Al: 0.01%~0.03%, the balance is Fe and unavoidable impurities, Ceq: 0.16~0.23%, Pcm: 0.07~0.13%.

technical field

[0001] The invention relates to the technical field of iron and steel smelting, in particular to a B-grade acid-resistant pipeline steel plate and a rolling process. Background technique

[0002] Due to the over-saturation of the steel market, the competitiveness of enterprises is becoming increasingly fierce, and the gross profit of conventional varieties is getting lower and lower. The development of high-grade products has become the key to the survival and development of enterprises. The demand for pipeline steel products in the international market is quite large. Due to the difficulty in production and the strict requirements on product quality, few companies have the qualifications to supply pipelines. For B-level acid-resistant export pipelines, Nb has always been used for tax rebates. Nb has a great effect on product microalloying and can refine the microstructure Granularity, anti-acid performance has no side effects, but the cost is higher. Conte...

Examples

Embodiment 1

[0032] A grade B acid-resistant pipeline steel plate provided in this example has the following chemical composition and mass percentage: C: 0.010%-0.017%, Si: 0.10%-0.20%, Mn: 0.80%-0.89%, P≤0.012% , S≤0.0008%, Ni: 0.10%~0.18%, Cu: 0.10%~0.15%, Nb: 0.03%~0.040%, Mo: 0.10%~0.15%, Ti: 0.01%~0.016%, Ca: 0.001% ~0.002%, Al: 0.010%~0.036%, the balance is Fe and unavoidable impurities, Ceq: 0.16~0.23%, Pcm: 0.07~0.13%.

[0033] The rolling process of the grade B acid-resistant pipeline steel plate includes the following steps:

[0034] S1. After surface inspection, the blank is sent to a walking heating furnace for heating. The austenitizing temperature is 1100-1110°C. The heating time is 9.6-11min / cm calculated based on the thickness of the billet, and the soaking time is more than 40min;

[0035] S2. The starting temperature of rough rolling is set at 1073°C, the finishing temperature of rough rolling is 985°C, the reduction rate of the penultimate pass of rough rolling is more ...

Embodiment 2

[0040] A grade B acid-resistant pipeline steel plate provided in this example differs from Example 1 in that its chemical composition and mass percentage are as follows: C: 0.020%-0.030%, Si: 0.20%-0.30%, Mn: 0.80% ~0.90%, P≤0.015%, S≤0.0010%, Ni: 0.15%~0.20%, Cu: 0.15%~0.20%, Nb: 0.025%~0.035%, Mo: 0.08%~0.13%, Ti: 0.01% ~0.02%, Ca: 0.001%~0.003%, Al: 0.02%~0.04%, the balance is Fe and unavoidable impurities, Ceq: 0.16~0.23%, Pcm: 0.07~0.13%.

Embodiment 3

[0042] A grade B acid-resistant pipeline steel plate provided in this example differs from Example 1 in that its chemical composition and mass percentage are as follows: C: 0.030%-0.040%, Si: 0.15%-0.25%, Mn: 0.80% ~0.90%, P≤0.015%, S≤0.0010%, Ni: 0.10%~0.15%, Cu: 0.10%~0.15%, Nb: 0.020%~0.030%, Mo: 0.10%~0.15%, Ti: 0.01% ~0.02%, Ca: 0.001%~0.003%, Al: 0.01%~0.03%, the balance is Fe and unavoidable impurities, Ceq: 0.16~0.23%, Pcm: 0.07~0.13%.

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