CN1075565C

CN1075565C - Hydrogen sulfide and chlorine ion corrosion resisting steel and its special equipment and fittings

Info

Publication number: CN1075565C
Application number: CN99116658A
Authority: CN
Inventors: 束润涛
Original assignee: Individual
Current assignee: Individual
Priority date: 1999-09-15
Filing date: 1999-09-15
Publication date: 2001-11-28
Anticipated expiration: 2019-09-15
Also published as: CN1280208A

Abstract

The present invention relates to steel which can resist the corrosion of hydrogen sulfide and chlorine ions, special equipment thereof and fittings thereof. The steel is produced by decreasing carbon content mainly on the basis of original low-alloy steel 12Cr2AlMoV which can resist the corrosion of hydrogen sulfide, and replacing vanadium (V) with poor welding performance by rare earth element with admirable performance, wherein the rare earth can not only improve and increase the performance of the steel and refine the crystal grains of the steel, but also increase the oxidation resistance and the corrosion resistance of the steel. The novel steel replacing the 12Cr2AlMoV is used to produce towers, containers, heat exchangers, air-cooled heat exchangers, filling materials, pipe lines, etc. of petrochemical units and other steel structures, other fastening parts, etc. which can resist the corrosion of hydrogen sulfide, seawater and bittern. The steel, special equipment thereof and fittings thereof which can resist the corrosion in the present invention can be widely used in petroleum industry, chemical industry, electric power industry, ocean engineering industry, etc.

Description

A kind of interchanger of rare earth alloy steel

The present invention relates to the heat exchanger device in the petrochemical unit.

Once there had been some positive exploration and researchs in China aspect the low-alloy steel grade of anti-H 2 S and chloride ion corrosion, I had also once declared on September 29th, 98 and had declared " steel pipe of moisture-resistant hydrogen sulfide corrosion and product for petrochemical equipment thereof " (application number 99116484.9) in " the special steel grades of two kinds of kinds of anti-sulfur corrosion " (application number 98121615.3), on May 24th, 99, main grade of steel is 12Cr2AlMoV and modified version 09Cr2AlMo, because there is the bad vanadium of welding property (V) in 12Cr2AlMoV in steel, after to change grade of steel after vanadium removed be 09Cr2AlMo.Simply remove vanadium and obviously have some irrationalities,, in steel, have crystal grain thinning, increase the plasticity and the toughness of steel though the existence of vanadium easily produces fragility in the weld.

The object of the present invention is to provide that a kind of welding property is good, plasticity good, easily processing and anti-H 2 S and chlorion (Cl ^-) corrosive new steel grade and specific equipment and accessory.

For realizing purpose of the present invention, now do further general introduction with regard to the technical program:

A kind of rare earth alloy steel basic technology of the present invention derives from the anti-H 2 S excellent property, and smelt and all comparatively sophisticated 12Cr2AlMoV steel grade of use, because 12Cr2AlMoV utilizes the comprehensive corrosion resistance of chromium (Cr), aluminium (Al), molybdenum (Mo), makes it have good anti-H 2 S (H ₂S) corrosive power, (the original application file is set forth), 98 years through hydrochloric acid (HCl) corrosion test contrast (seeing Table 1)

The corrosion test contrast of table 1 in hydrochloric acid (HCl)

Grade of steel	100 ℃, 36%HCl corrosion rate (mg/cm ².h)	80 ℃, 5%HCl corrosion rate (mg/cm ².h)
Grade of steel	100 ℃, 36%HCl corrosion rate (mg/cm ².h)	80 ℃, 5%HCl corrosion rate (mg/cm ².h)	10 ^#	119.23	233.8
10 ^#Aluminising	194.62	179.83	10 ^#	119.23	233.8
10 ^#Aluminising	194.62	179.83	12Cr2AlMoV	9.23	20.06

Annotate: 1. 100 ℃, the test period of 36%HCl are hot dipping 3 hours (h);

2. 80 ℃, the test period of 5%HCl are hot dipping 16 hours (h).And at the sea water cooler of Dalian oil seven factories and the Atmospheric Tower (H of Huhehaote refinery ₂S-HCl-H ₂O) use in the environment, its anti-seawater chlorion and anti-hydrochloric acid (HCl) corrosion aspect have tangible resistance to corrosion.The former use carbon steel (10 of Huhehaote refinery Atmospheric Tower ^#) heat exchanger tube just must be changed less than three months, and use 12Cr2AlMoV does not find any leakage accident after nearly 1 year, Dalian oil seven factories and Chang Ling refinery are at seawater and chlorion (Cl ^-) also effect is obvious after using 12Cr2AlMoV in the corrosive environment.However, still there is certain incompatibility factor in 12Cr2AlMoV in the process of device fabrication, is mainly reflected in to exist caused welding property relatively poor because of vanadium (V).Therefore afterwards from removing vanadium (V), reducing carbon (C) content aspect this steel is improved, determine that its grade of steel is 09Cr2AlMo or 10Cr2AlMo.But in the Chemical Composition of a comparatively sophisticated steel grade 12Cr2AlMoV, simply remove vanadium (V), though can improve its material welding performance, but lost in the material existence crystal grain thinning because of vanadium (V), stablize the effect of its Chemical Composition, therefore the corrosion resistance of its material can reduce.Therefore, under the prerequisite of mechanical property of making every effort to improve 12Cr2AlMoV and welding property, should be replaced by chemical element niobium (Nb) or the rare earth (RE) that has corresponding effect with it after removing vanadium (V), niobium (Nb) and rare earth are the same with vanadium (V) in smelting iron and steel to have a crystal grain thinning, improve the mechanical property of material, and cold working and welding property are all much superior than vanadium (V), the steel that contains vanadium (V) easily produces certain fragility after welding, cold-bending property is also relatively poor, and the steel alloy that contains niobium (Nb) or rare earth (RE) can improve Drawing abillity and welding property, particularly rare earth can play deoxidation and desulfurization in steel-making, and can improve the intensity of steel, plasticity, toughness, erosion resistance and oxidation-resistance are added the anti-oxidant rate that rare earth can improve steel in the Fc-Cr-Al alloy, increase resistivity, erosion resistance and hot strength (seeing " material voluminous dictionary " P1004 page or leaf " rare earth metal ").In order to improve the welding property of 12Cr2AlMoV, the not loss of reason vanadium (V) and make the crystal grain of steel become big again replaces vanadium with rare earth simultaneously, and it is as follows to reduce after the carbon content Chemical Composition of new steel grade:

Table 2 chemical ingredients (%)

There is not plain symbol	C	Mn	Si	Cr	Al	Mo	RE	S、P
There is not plain symbol	C	Mn	Si	Cr	Al	Mo	RE	S、P	Ratio	≤0.12％	0.30～1.50	0.30～0.70	1.80～2.30	0.30～0.80	0.30～0.80	0.04～0.20	≤0.035
Permissible variation	+0.02	±0.2	±0.1	±0.5	±0.1	±0.1	±0.02	+0.01	Ratio	≤0.12％	0.30～1.50	0.30～0.70	1.80～2.30	0.30～0.80	0.30～0.80	0.04～0.20	≤0.035

Annotate: surplus is by the Fe balance

According to the Chemical Composition scope in the table, when the material of refining different varieties, should do corresponding adjustment, when with this steel refining sheet material and section bar, need higher mechanical properties, carbon (C) content capping value (C≤0.12%, permissible variation+0.02%) then, manganese (Mn) content should higher (Mn:0.8～1.5%, permissible variation scholar 0.1%), can determine that according to its carbon (C) and other anti-corrosion element its grade of steel is 10Cr2AlMoRE or 12Cr2AlMoRE this moment; When refine special-purpose interchanger tubing of petrochemical industry or book plate (δ: in the time of 0.2～3.0mm) with this steel, need lower mechanical property and good processing properties, then carbon (C) content suitably reduces (C≤0.09%, permissible variation+0.01%), manganese (Mn) content also should be turned down (Mn:0.3～0.7% simultaneously, permissible variation scholar 0.1, other elementary composition is constant, can determine that thus its grade of steel name is called 09Cr2AlMoRE or 08Cr2AlMoRE.Mechanical property is as follows respectively:

Table 3 mechanical property

Grade of steel	Yield-point σ _aMPa	Tensile strength sigma _bMPa	Hardness HB	Elongation δ _s％
Grade of steel	Yield-point σ _aMPa	Tensile strength sigma _bMPa	Hardness HB	Elongation δ _s％	08～09Cr2AlMoRE	≥210	350～500	≤158	≥25
10～12Cr2AlMoRE	≥310	≥410	≥160	≥19	08～09Cr2AlMoRE	≥210	350～500	≤158	≥25

Novel material can be produced the steel products such as steel, section bar, tubing of different size and model according to its purposes.

In order to make novel material is the national economy service, can make it with sheet material, section bar, the tubing of novel material and have hydrogen sulfide (H ₂S) and chlorion (Cl ^-) pressurized vessel, tower, interchanger, air cooler, pipeline, tower tray and the chemical filler etc. of corrosive environment.Used welding rod be " R307 rare earth (RE) " when making specific equipment such as pressurized vessel and accessory with new steel grade, promptly in the chemical ingredients of standard " R307 " welding rod interpolation as the content (0.04～0.2%) of steel Chemical Composition middle-weight rare earths (RE).

The present invention---anti-H 2 S (H ₂S) and chlorion (Cl ^-) advantage of corrosive steel and equipment and accessory is:

1. novel material is compared with 12Cr2AlMoV, and the vanadium (V) owing to replace having welding flaw with the rare earth of superior performance has not only improved welding property, but also increased plasticity, oxidation-resistance and the solidity to corrosion of steel.

2. because rare earth plays deoxidation and desulfurization in steel-making, foreign matter content in the steel just can greatly reduce, the working control of its steel sulphur (S) content in refining is only below 0.005%, more much lower than the sulphur (S)≤0.035% that requires among the GB150-1998 " Steel Pressure Vessels ", have fabulous resisting sulfide stress corrosion performance.

According to diagram the present invention is done further general introduction below:

Fig. 1 is a container, makes the housing (part 1) and the intubate (part 2) of container of 10～12Cr2AlMoRE;

Fig. 2 is a tower, makes housing (part 1) and intubate (part 2), tower tray (part 3) and the filler (part 4) of tower of 10～12Cr2AlMoRE;

Fig. 3 is an interchanger, with housing (part 1) and intubate (part 2) and the tube sheet (part 3) and the traverse baffle (part 4) of 10～12Cr2AlMoRE making interchanger, makes the heat transfer tube (part 5) of interchanger of the fluid tubing of 08～09Cr2AlMoRE;

Fig. 4 is an air cooler, and bobbin carriage (part 1) intubate (part 2) of making air cooler with 10～12Cr2AlMoRE is with the finned tube (part 3) of the thin plate manufacturing air cooler of the fluid tubing of 08～09Cr2AlMoRE and 0.2～0.8mm;

Fig. 5 is a tower tray, with the tower tray in the board making tower of 10～12Cr2AlMoRE;

Fig. 6 is various chemical fillers, makes the diffusing heap and the structured packing of petrochemical industry with the thin plate of 08～09Cr2AlMoRE.

Fig. 7 is a pipeline, rolls the back welding with the sheet material of 10～12Cr2AlMoRE, can do threaded pipe (part 1), vertical masonry joint pipe (part 2) or splicing welded tube (part 3).

Claims

1. rare earth alloy steel interchanger, it is made of housing (1), intubate (2), tube sheet (3), traverse baffle (4) and heat transfer tube (5), it is characterized in that: its described housing (1), intubate (2), tube sheet (3), traverse baffle (4) are done with 10～12Cr2AlMoRE steel, heat transfer tube (5) the fluid tubing of 09Cr2AlMoRE steel.

2. as claims 1 described rare earth alloy steel interchanger, it is characterized in that: the chemical ingredients of its described 09～12Cr2AlMoRE steel is: C :≤0.12%, Mn:0.30～1.50%, Si:0.30～0.70%, Cr:1.80～2.30%, Al:0.30～0.80%, Mo:0.30～0.80%, RE:0.04～0.20%, S :≤0.035%, P :≤0.035%, surplus is by the Fe balance.