Non-chlorine system seamless stainless steel pipe cold rolling process oil composition and preparation method thereof

Abstract

The application discloses a kind of non-chlorine system seamless stainless steel pipe cold rolling process oil composition, by the following components by mass percentage consists of: base oil 60%~80%, phosphate ester ammonium salt 5%~10%, extreme pressure agent 5%~10%, borate ester ammonium salt 6%~12%, high molecular polyester 3%~7%, antioxidant 0.1%~0.3%, rust inhibitor 0.4%~1%, corrosion inhibitor 0.1%~0.5%, the total of above raw material mass percentage is 100%.The application also discloses the preparation method of the composition, phosphate ester ammonium salt, extreme pressure agent, borate ester ammonium salt, antioxidant, rust inhibitor, corrosion inhibitor are added in the stirred tank containing base oil, stirring to dissolve, then high molecular polyester is added, heating stirring is completely dissolved, the filtrate after filtration is the composition of the application.The product of the application does not contain chlorinated paraffin and other chlorine agent, has excellent extreme pressure performance and lubricating property.

Description

Technical Field

[0001] This invention belongs to the field of metal processing oil technology, and relates to a non-chlorine system seamless stainless steel tube cold rolling process oil composition. This invention also relates to a method for preparing the above-mentioned non-chlorine system seamless stainless steel tube cold rolling process oil composition. Background Technology

[0002] Currently, my country has become the world's largest producer, consumer, and exporter of stainless steel pipes, with production scale and quality reaching international advanced levels, and a self-sufficiency rate exceeding 90%. In 2020, China produced approximately 2.8 × 10⁻⁶ seamless steel pipes. 7 Tons, including approximately 1.2 × 10⁻⁶ seamless stainless steel pipes. 6 Tons. Based on preliminary calculations of oil consumption during the cold rolling process of stainless steel pipes, the annual oil demand for the cold rolling process of steel pipes is no less than 10,000 tons.

[0003] However, while China's stainless steel pipe industry is booming, it also faces bottlenecks in structural adjustment, transformation and upgrading, and high-quality development. The lubricating oil used in the production process of seamless stainless steel pipes is a typical example of a technology urgently needing transformation and upgrading. Currently, the main lubricant used in the cold rolling of seamless stainless steel pipes in China is chlorinated paraffin-containing rolling oil. It is worth noting that the fumes generated by chlorinated paraffin-containing cold rolling oil during heat treatment have a significant environmental impact, are difficult to treat to meet emission standards, and the pickling and rinsing wastewater is also difficult to treat, which is detrimental to improving the quality of stainless steel pipes.

[0004] Although chlorinated paraffins have good application performance, their non-degradability and the potential formation of dioxins at high temperatures can lead to their release into local areas, posing a significant environmental hazard. With increasing international awareness of the dangers of chlorinated paraffins and increasingly stringent environmental regulations in China, the use of chlorinated paraffins, especially short-chain chlorinated paraffins with a carbon number of 10-13, has been limited to a mass fraction of ≤1%. While chlorinated paraffins with a carbon number greater than 13 are not restricted, their environmental harm remains, and they will inevitably be phased out of the formulation systems for such process oils. Summary of the Invention

[0005] The purpose of this invention is to provide a non-chlorine system oil composition for the cold rolling process of seamless stainless steel pipes, which solves the problem that existing oil compositions for the cold rolling process of seamless stainless steel pipes contain chlorinated agents such as chlorinated paraffin.

[0006] Another object of the present invention is to provide a method for preparing the above-mentioned non-chlorine system seamless stainless steel tube cold rolling process oil composition.

[0007] The technical solution adopted in this invention is a non-chlorine system seamless stainless steel tube cold rolling process oil composition, which is composed of the following components by mass percentage: base oil 60% to 80%, ammonium phosphate salt 5% to 10%, extreme pressure agent 5% to 10%, ammonium borate salt 6% to 12%, high molecular weight polyester 3% to 7%, antioxidant 0.1% to 0.3%, rust inhibitor 0.4% to 1%, corrosion inhibitor 0.1% to 0.5%, and the total mass percentage of the above raw materials is 100%.

[0008] The present invention is further characterized in that: the base oil is at least one of trimethylolpropane oleate, Span 80 or Tween 80; when the base oil is a combination of two or more of trimethylolpropane oleate, Span 80 and Tween 80, the mass ratio of trimethylolpropane oleate, Span 80 and Tween 80 is 1-3:2-4:3-5.

[0009] The ammonium phosphate salt is at least one of phosphate ester T308, ammonium phosphate salt Vanlube692, or ammonium phosphate salt Vanlube672; when the ammonium phosphate salt is a combination of two or more of phosphate ester T308, ammonium phosphate salt Vanlube692, or ammonium phosphate salt Vanlube672, the mass ratio of T308, ammonium phosphate salt Vanlube692, and ammonium phosphate salt Vanlube672 is 1-2:1-2:2-3.

[0010] The extreme pressure agent is at least one of T109, T106 or T106D; when the extreme pressure agent is a combination of two or more of T109, T106 or T106D, the mass ratio of T109, T106 and T106D is 1~2:2~3:1~2.

[0011] The ammonium borate ester is at least one of dicyclohexylamine borate ester, triethanolamine borate ester, or diethanolamine borate ester; when the ammonium borate ester is a combination of two or more of the following, the mass ratio of the two or more of them is 1-2:2-4:2-3.

[0012] The polymeric polyester is at least one of GY-25 or Croda3986; when the polymeric polyester is a combination of GY-25 and Croda3986, the mass ratio of GY-25 to Croda3986 is 2-5:2-3.

[0013] It is composed of antioxidants T501, L57 and L115, with a mass ratio of T501:L57:L115 of 1~2:1~2:2~3.

[0014] The rust inhibitor is at least one of T746 or naphthenic acid; when the rust inhibitor is a combination of T746 and naphthenic acid, the mass ratio of T746 to naphthenic acid is 1-2:2-3.

[0015] The corrosion inhibitor is any one of benzotriazole or triazole derivatives; the triazole derivative is BASF IR42.

[0016] Another technical solution adopted in this invention is a method for preparing a non-chlorine system seamless stainless steel tube cold rolling process oil composition, which is specifically implemented according to the following steps:

[0017] Step 1: Weigh the following by mass percentage: base oil 60%–80%, ammonium phosphate salt 5%–10%, extreme pressure agent 5%–10%, ammonium borate salt 6%–12%, high molecular weight polyester 3%–7%, antioxidant 0.1%–0.3%, rust inhibitor 0.4%–1%, corrosion inhibitor 0.1%–0.5%, and the total mass percentage of the above raw materials shall be 100%.

[0018] Step 2: Add the base oil weighed in Step 1 to the mixing tank, and add the ammonium phosphate salt, extreme pressure agent, ammonium borate salt, antioxidant, rust inhibitor and corrosion inhibitor weighed in Step 1 to the base oil. Stir until completely dissolved to obtain mixture A.

[0019] Step 3: Add the high molecular weight polyester weighed in Step 1 to mixture A obtained in Step 2, heat and stir until completely dissolved, the heating temperature should not exceed 80℃; to obtain mixture B;

[0020] Step 4: Filter the mixture B obtained in Step 3 using a 150-250 mesh filter bag. The filtrate is the composition of the present invention.

[0021] The beneficial effects of this invention are: the product of this invention does not contain chlorinated paraffin or other chlorine agents, has excellent extreme pressure performance and lubrication performance, meets the performance requirements of rolling mills for rolling oil under large-area working conditions of rolling pipe diameter φ60mm~φ450mm, and can improve the quality of steel pipes, with no subsequent corrosion problems. Detailed Implementation

[0022] The present invention will now be described in detail with reference to specific embodiments.

[0023] This invention discloses a non-chlorine system oil composition for cold rolling of seamless stainless steel pipes, comprising the following components by mass percentage: 60%–80% base oil, 5%–10% ammonium phosphate salt, 5%–10% extreme pressure agent, 6%–12% ammonium borate salt, 3%–7% high molecular weight polyester, 0.1%–0.3% antioxidant, 0.4%–1% rust inhibitor, and 0.1%–0.5% corrosion inhibitor, with the total mass percentage of the above raw materials being 100%.

[0024] Preferably, the base oil is at least one of trimethylolpropane oleate, Span 80, or Tween 80; when the base oil is a combination of two or more of trimethylolpropane oleate, Span 80, and Tween 80, the mass ratio of trimethylolpropane oleate, Span 80, and Tween 80 is 1-3:2-4:3-5.

[0025] Preferably, the ammonium phosphate salt is at least one of phosphate ester T308, ammonium phosphate salt Vanlube692, or ammonium phosphate salt Vanlube672; when the ammonium phosphate salt is a combination of two or more of phosphate ester T308, ammonium phosphate salt Vanlube692, or ammonium phosphate salt Vanlube672, the mass ratio of T308, ammonium phosphate salt Vanlube692, and ammonium phosphate salt Vanlube672 is 1-2:1-2:2-3.

[0026] Preferably, the extreme pressure agent is at least one of T109, T106, or T106D; when the extreme pressure agent is a combination of two or more of T109, T106, or T106D, the mass ratio of T109, T106, and T106D is 1-2:2-3:1-2.

[0027] Preferably, the ammonium borate salt is at least one of dicyclohexylamine borate ammonium salt, triethanolamine borate ammonium salt, or diethanolamine borate ammonium salt; when the ammonium borate salt is a combination of two or more of the following, the mass ratio of dicyclohexylamine borate ammonium salt, triethanolamine borate ammonium salt, or diethanolamine borate ammonium salt is 1-2:2-4:2-3.

[0028] Preferably, the polymeric polyester is at least one of GY-25 or Croda3986; when the polymeric polyester is a combination of GY-25 and Croda3986, the mass ratio of GY-25 to Croda3986 is 2-5:2-3.

[0029] Preferably, the composition consists of antioxidants T501, L57 and L115, with a mass ratio of T501:L57:L115 of 1-2:1-2:2-3.

[0030] Preferably, the rust inhibitor is at least one of T746 or naphthenic acid; when the rust inhibitor is a combination of T746 and naphthenic acid, the mass ratio of T746 to naphthenic acid is 1-2:2-3.

[0031] Preferably, the corrosion inhibitor is any one of benzotriazole or a triazole derivative; the triazole derivative is BASF IR42.

[0032] The principles for selecting the values ​​of base oil, ammonium phosphate salt, extreme pressure agent, ammonium borate salt, polymer polyester, antioxidant, rust inhibitor, and corrosion inhibitor in the non-chlorine system seamless stainless steel tube cold rolling process oil composition of the present invention are as follows:

[0033] Base oil: The preferred amount of base fluid is 60% to 80%. If the amount is less than 60%, it will cause problems such as unreasonable product viscosity, reduced cleaning performance, and poor dissolution of additives, resulting in turbidity or even precipitation in the oil. If the amount is greater than 80%, it will cause problems such as unsuitable product viscosity, insufficient lubrication performance, and excessive viscosity changes in high and low temperature conditions, without any other benefits.

[0034] Ammonium phosphate salt: The preferred dosage of ammonium phosphate salt is 5-10%; if the dosage is less than 5%, the dosage is too low and the wear resistance of the product will be insufficient, resulting in damage to the quality of the steel pipe; if the dosage is greater than 10%, the dosage is too high and the product cost will increase without any other benefits.

[0035] Extreme pressure agent: The preferred dosage of extreme pressure agent is 5-10%; if the dosage is less than 5%, it will result in insufficient lubrication film formation reaction under high temperature conditions above 500°C; if the dosage is greater than 10%, it will result in poor appearance of process oil, significantly increase cost, and provide no other benefits.

[0036] Ammonium borate ester: The preferred dosage of ammonium borate ester is 6% to 12%. If the dosage is less than 6%, it will be too low and the product's adsorption and film-forming ability will decrease. If the dosage is greater than 12%, it will be too high and the machine tool will be difficult to clean. At the same time, it will significantly increase the product cost without any other benefits.

[0037] Polyester polymer: The preferred amount of polyester polymer is 3-7%; if the amount is less than 3%, it will result in insufficient adhesion and lubrication properties of the product; if the amount is greater than 7%, it will result in increased product cost without any other benefits.

[0038] Antioxidant: The preferred dosage of antioxidant is 0.1-0.3%; if the dosage is less than 0.1%, it will be too low and cause insufficient antioxidant properties in the product, resulting in spoilage; if the dosage is greater than 0.3%, it will be too high and increase the product cost without any other benefits.

[0039] Rust inhibitor: The preferred dosage of rust inhibitor is 0.4% to 1%. If the dosage is less than 0.4%, it will be too low and the product will not be able to prevent rust and disperse properly. If the dosage is greater than 1%, it will be too high and the product cost will increase significantly without any other benefits.

[0040] Corrosion inhibitor: The preferred dosage of corrosion inhibitor is 0.1-0.5%; if the dosage is less than 0.1%, it is too low and will cause corrosion of the workpiece; if the dosage is greater than 0.5%, it is too high and will significantly increase product costs without any other benefits.

[0041] The preparation method of the non-chlorine system seamless stainless steel tube cold rolling process oil composition of the present invention is specifically implemented according to the following steps:

[0042] Step 1: Weigh the following by mass percentage: base oil 60%–80%, ammonium phosphate salt 5%–10%, extreme pressure agent 5%–10%, ammonium borate salt 6%–12%, high molecular weight polyester 3%–7%, antioxidant 0.1%–0.3%, rust inhibitor 0.4%–1%, corrosion inhibitor 0.1%–0.5%, and the total mass percentage of the above raw materials shall be 100%.

[0043] Step 2: Add the base oil weighed in Step 1 to the mixing tank, and add the ammonium phosphate salt, extreme pressure agent, ammonium borate salt, antioxidant, rust inhibitor and corrosion inhibitor weighed in Step 1 to the base oil. Stir until completely dissolved to obtain mixture A.

[0044] Step 3: Add the high molecular weight polyester weighed in Step 1 to mixture A obtained in Step 2, heat and stir until completely dissolved, the heating temperature should not exceed 80℃; to obtain mixture B;

[0045] Step 4: Filter the mixture B obtained in Step 3 using a 150-250 mesh filter bag. The filtrate is the composition of the present invention.

[0046] Example 1

[0047] The preparation method of the non-chlorine system seamless stainless steel tube cold rolling process oil composition is carried out according to the following steps:

[0048] Step 1: Weigh out the following by weight percentage: Trimethylolpropane oleate, 20%; Tween 80, 60%; T308, 5%; T106, 3%; T106D, 2%; Triethanolamine borate ammonium salt, 6%; GY-25, 3%; T501, 0.025%; L57, 0.025%; L115, 0.05%; T746, 0.8%; Benzotriazole, 0.1%.

[0049] Step 2: Add the trimethylolpropane oleate and Tween 80 weighed in Step 1 to a stirred tank. Add the T308, T106, T106D, triethanolamine borate ammonium salt, T501, L57, L115, T746, and benzotriazole weighed in Step 1 to the trimethylolpropane oleate and Tween 80. Stir until completely dissolved to obtain mixture A.

[0050] Step 3: Add the GY-25 weighed in Step 1 to mixture A obtained in Step 2, heat and stir until completely dissolved, the heating temperature is 80℃; to obtain mixture B;

[0051] Step 4: Filter the mixture B obtained in Step 3 using a 200-mesh filter bag. The filtrate is the composition of the present invention.

[0052] Example 2

[0053] The preparation method of the non-chlorine system seamless stainless steel tube cold rolling process oil composition is carried out according to the following steps:

[0054] Step 1: Weigh out the following by mass percentage: Span 80, 60%; Vanlube 672 ammonium phosphate, 10%; T109, 10%; diethanolamine borate ammonium salt, 12%; Croda 3986, 7%; T501, 0.04%; L57, 0.04%; L115, 0.06%; naphthenic acid, 0.66%; BASF IR42, 0.2%.

[0055] Step 2: Add the Span 80 weighed in Step 1 to the stirred tank, and add the ammonium phosphate salt Vanlube 672, T109, diethanolamine borate ammonium salt, T501, L57, L115, naphthenic acid, and BASF IR42 weighed in Step 1 to the Span 80. Stir until completely dissolved to obtain mixture A.

[0056] Step 3: Add the Croda3986 weighed in Step 1 to mixture A obtained in Step 2, heat and stir until completely dissolved, the heating temperature is 75℃; to obtain mixture B;

[0057] Step 4: Filter the mixture B obtained in Step 3 using a 150-mesh filter bag. The filtrate is the composition of the present invention.

[0058] Example 3

[0059] The preparation method of the non-chlorine system seamless stainless steel tube cold rolling process oil composition is carried out according to the following steps:

[0060] Step 1: Weigh the following by weight percentage: Trimethylolpropane oleate, 18%; Tween 80, 24%; Span 80, 30%; T308, 2.5%; Ammonium phosphate salt Vanlube 672, 2.5%; T106, 3.5%; T106D, 3.5%; Triethanolamine borate ammonium salt, 5.5%; Diethanolamine borate ammonium salt, 5.5%; GY-25, 3.2%; T501, 0.1%; L57, 0.1%; L115, 0.1%; T746, 0.4%; Naphthenic acid, 0.6%; Benzotriazole, 0.5%.

[0061] Step 2: Add the trimethylolpropane oleate, Tween 80, and Span 80 weighed in Step 1 to a stirred tank. Add the following ingredients weighed in Step 1: T308, ammonium phosphate salt Vanlube 672, T106, T106D, triethanolamine borate ammonium salt, diethanolamine borate ammonium salt, T501, L57, L115, T746, naphthenic acid, and benzotriazole. Stir until completely dissolved to obtain mixture A.

[0062] Step 3: Add the GY-25 weighed in Step 1 to mixture A obtained in Step 2, heat and stir until completely dissolved, the heating temperature is 70℃; to obtain mixture B;

[0063] Step 4: Filter the mixture B obtained in Step 3 using a 250-mesh filter bag. The filtrate is the composition of the present invention.

[0064] Example 4

[0065] Based on the total mass of the process oil composition, select according to the following mass percentages:

[0066] Span 80, 26%; Tween 80, 39%; Ammonium phosphate Vanlube 692, 9%; T109, 3.6%; T106, 5.4%; Dicyclohexylamine borate ammonium salt, 10%; GY-25, 3%; Croda 3986, 3%; T501, 0.04%; L57, 0.04%; L115, 0.12%; T746, 0.3%; Naphthenic acid, 0.3%; Benzotriazole, 0.2%;

[0067] The preparation method is as described in Example 1.

[0068] Example 5

[0069] Based on the total mass of the process oil composition, select according to the following mass percentages:

[0070] Trimethylolpropane oleate, 70%; T308, 4%; Ammonium phosphate salt Vanlube692, 4%; T106, 8%; Dicyclohexylamine borate ammonium salt, 3%; Triethanolamine borate ammonium salt, 6%; GY-25, 4%; T501, 0.1%; L57, 0.1%; L115, 0.1%; T746, 0.1%; Naphthenic acid, 0.3%; Benzotriazole, 0.3%.

[0071] The preparation method is as described in Example 1.

[0072] Example 6

[0073] Based on the total mass of the process oil composition, select according to the following mass percentages:

[0074] Tween 80, 75%; Ammonium phosphate Vanlube 692, 2%; Ammonium phosphate Vanlube 672, 4%; T106D, 6%; Dicyclohexylamine borate ammonium salt, 3.2%; Diethanolamine borate ammonium salt, 4.8%; GY-25, 2.5%; Croda 3986, 1.5%; T501, 0.04%; L57, 0.04%; L115, 0.12%; T746, 0.2%; Naphthenic acid, 0.2%; BASF IR42, 0.4%.

[0075] The preparation method is as described in Example 1.

[0076] Example 7

[0077] Based on the total mass of the process oil composition, select according to the following mass percentages:

[0078] Trimethylolpropane oleate, 25%; Span 80, 50%; T308, 2%; Ammonium phosphate Vanlube 692, 2%; Ammonium phosphate Vanlube 672, 3%; T109, 1.3%; T106, 2.6%; T106D, 1.3%; Dicyclohexylamine borate ammonium salt, 1.6%; Triethanolamine borate ammonium salt, 3.2%; Diethanolamine borate ammonium salt, 2.4%; Croda 3986, 3.9%; T501, 0.1%; L57, 0.1%; L115, 0.1%; T746, 0.3%; Naphthenic acid, 0.6%; BASF IR42, 0.5%.

[0079] The preparation method is as described in Example 1.

[0080] The non-chlorine system seamless stainless steel tube cold rolling process oil composition of the present invention was tested, and the results are as follows:

[0081] The inventor purchased a typical imported seamless stainless steel pipe cold rolling process oil product currently available on the market and conducted relevant physicochemical property tests. The results are shown in Table 1. The main components of this product are: base oil, chlorinated paraffin, synthetic ester, sulfurized olefins, and other additives.

[0082] Table 1. Comparison of the physicochemical and performance characteristics of the present invention with a typical product currently on the market.

[0083]

[0084] The seamless stainless steel tube cold rolling process oil provided by this invention does not contain chlorinated paraffin or other chlorinated extreme pressure agents. As can be seen from the test data in Table 1, its lubrication extreme pressure performance fully reaches the level of products containing chlorinated agents, especially in terms of the P-value, which reflects the product's lubrication performance. BThe value is more than three times that of commercially available products. Furthermore, the product of this invention has lower kinematic viscosity, making operation simpler; the product exhibits excellent corrosion and rust prevention, achieving a copper sheet corrosion rating of Level 1, while commercially available products are at Level 4. Subsequent usage tests conducted at a seamless stainless steel pipe factory in Lishui, Zhejiang Province, also fully demonstrated that the product of this invention meets the requirements of the cold rolling process for seamless stainless steel pipes, is environmentally friendly and pollution-free, and produces no odor in the workshop.

Claims

1. A non-chlorine system oil composition for cold rolling of seamless stainless steel pipes, characterized in that, It is composed of the following components by weight percentage: base oil 60%~80%, ammonium phosphate salt 5%~10%, extreme pressure agent 5%~10%, ammonium borate salt 6%~12%, high molecular weight polyester 3%~7%, antioxidant 0.1%~0.3%, rust inhibitor 0.4%~1%, and corrosion inhibitor 0.1%~0.5%; The base oil is at least one of trimethylolpropane oleate, Span 80, and Tween 80; The boronic acid ester ammonium salt is a mixture of dicyclohexylamine boronic acid ester ammonium salt, triethanolamine boronic acid ester ammonium salt, and diethanolamine boronic acid ester ammonium salt; the mass ratio of the dicyclohexylamine boronic acid ester ammonium salt, triethanolamine boronic acid ester ammonium salt, and diethanolamine boronic acid ester ammonium salt is 1~2:2~4:2~3; The polymeric polyester is at least one of GY-25 or Croda3986; The rust inhibitor is a mixture of T746 and naphthenic acid; the mass ratio of T746 to naphthenic acid is 1~2:2~3; The extreme pressure agent is a mixture of T109, T106 and T106D; The ammonium phosphate salt is a mixture of T308, ammonium phosphate salt Vanlube692, and ammonium phosphate salt Vanlube672; The antioxidant is composed of T501, L57 and L115, and the mass ratio of T501:L57:L115 is 1~2:1~2:2~3.

2. The non-chlorine system seamless stainless steel tube cold rolling process oil composition according to claim 1, characterized in that, The mass ratio of T109, T106 and T106D is 1~2:2~3:1~2.

3. The non-chlorine system seamless stainless steel tube cold rolling process oil composition according to claim 1, characterized in that, The mass ratio of T308, ammonium phosphate salt Vanlube692, and ammonium phosphate salt Vanlube672 is 1~2:1~2:2~3.

4. The non-chlorine system seamless stainless steel tube cold rolling process oil composition according to claim 1, characterized in that, The corrosion inhibitor is benzotriazole or BASF IR42.

5. The method for preparing the non-chlorine system seamless stainless steel tube cold rolling process oil composition according to any one of claims 1 to 4, characterized in that, The specific steps are as follows: Step 1: Weigh the following by weight percentage: base oil 60%~80%, ammonium phosphate salt 5%~10%, extreme pressure agent 5%~10%, ammonium borate salt 6%~12%, high molecular weight polyester 3%~7%, antioxidant 0.1%~0.3%, rust inhibitor 0.4%~1%, corrosion inhibitor 0.1%~0.5%; Step 2: Add the base oil weighed in Step 1 to the mixing tank, and add the ammonium phosphate salt, extreme pressure agent, ammonium borate salt, antioxidant, rust inhibitor and corrosion inhibitor weighed in Step 1 to the base oil. Stir until completely dissolved to obtain mixture A. Step 3: Add the high molecular weight polyester weighed in Step 1 to mixture A obtained in Step 2, heat and stir until completely dissolved, the heating temperature should not exceed 80℃; to obtain mixture B; Step 4: Filter the mixture B obtained in Step 3 using a 150-250 mesh filter bag. The filtrate is the non-chlorine system seamless stainless steel pipe cold rolling process oil composition.

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