CN101537544A - Electric welding rod for welding large scale low temperature spherical tank steel - Google Patents

Abstract

The invention relates to an electric welding rod for welding large scale low temperature spherical tank steel, consisting of a core welding-wire, an electrode covering and adhesive. The electric welding rod is manufactured according to the conventional manufacturing technique of the electric welding rod; the strength and the toughness of the electric welding rod can be enhanced by strictly controlling the lower percentage composition of S and P in auxiliary materials of the core welding-wire and the electrode covering. The invention has the advantages that the ultralow hydrogen sodium type electric welding rod has high strength and toughness, good welding technological properties, easy arc initiation, soft voltaic arc, little splatter, convenient slag detachability, delicate shaped weld mark, beautiful appearance and all-position welding; deposited metal is well purified and thinned, and has excellent low-temperature impact ductility and cracking resistance, low content of diffusible hydrogen as well as good performances of hot crack and cold crack resistance as well as reheating crack resistance; the welded deposited metal adapts to wide range of heat treatment parameter and has good actual construction adaptability, thus being applicable to welding a spherical tank, especially large scale spherical tanks made of propylene, ethylene and LPG.

Description

A kind of welding rod that is used for the large scale low temperature spherical tank steel welding

Technical field:

The present invention relates to welding material of metal, particularly a kind of welding rod that is used for the large scale low temperature spherical tank steel welding.

Background technology:

Along with the China's Petrochemical fast development, all kinds of storage liquid liquefied oil gas that are used for, large scale low temperature spherical tanks such as natural gas, ethene, propylene have had very big demand.Along with the spherical tank volume increases, require to improve the tensile strength rank lower limit of steel plate, realize the attenuate of balls coverboard thickness.In the manufacturing of large scale low temperature spherical tank, except quality requirement, the performance of supporting welding material also there is the requirement of strictness to steel plate materials.China has adopted the 610MPa low welding crack sensibility high-strength steel plate manufacturing-50 ℃ large scale low temperature spherical tank of production domesticization import at present, but used welding material relies on external import to a great extent, especially whole dependence on import especially in making the large-scale low-temperature spherical ethylene tank, subject matter is under the minimum serviceability temperature of spherical tank, homemade welding material deposited metal and weld metal, do not reach requirement in as-welded low-temperature impact absorption merit following and that eliminate stress after handling through the long-time postwelding of high temperature, single low value appears easily, aspect such as crack resistance and anti-reheat crack(ing), can't satisfy the needs of making large scale low temperature spherical tank, for example present China J607RH welding rod, tensile strength can satisfy-20 ℃ of low temperature spherical tank steel standard-requireds for the 610MPa rank, but low-temperature impact toughness can not reach the class requirement of-60 ℃ of time 〉=60J fully, and measured value is Akv (ballistic work-60 ℃)=35J.

Summary of the invention:

The objective of the invention is at above-mentioned existing problems, but provide that a kind of welding procedure is good, striking is easy, electric arc is soft, splash few, take off slag easily, weld ripples be shaped careful all-position welding attractive in appearance, the deposited metal refinement is good and have the welding rod that large scale low temperature spherical tank steel welds that is used for of good low temperature impact flexibility, crack resistance and anti-reheat crack(ing).

Technical scheme of the present invention:

A kind of welding rod that is used for the large scale low temperature spherical tank steel welding is made up of core wire, electrode coating and adhesive, and the welding rod production technology is made routinely,

1) core wire is H08GX welding rod wire rod, its contained chemical composition and percentage by weight such as following table: (%)

C	S	Mn	Si	P	Fe
						0.05-0.08	≤0.004	0.30-0.60	≤0.030	≤0.006	Surplus

2) electrode coating comprises following auxiliary material and percentage by weight such as following table: (%)

Marble	Fluorite	Rutile	Silicon powder	Ferromanganese	Ferrosilicon	Ferrotianium	Nickel powder	Ferro-boron	Molybdenum-iron	Iron powder
											30-40	13-17	4-7	3-5	3-5	3-4	6-8	8-10	0.5-1	0.5-1	Surplus

, wherein the percentage by weight of S, P control index is in following auxiliary material: (%)

Coating auxiliary material title	Marble	Fluorite	Ferrosilicon	Ferrotianium	Iron powder	Silicon powder
							S	≤0.005	≤0.005	≤0.010	≤0.010	≤0.005	≤0.005
P	≤0.005	≤0.005	≤0.010	≤0.010	≤0.003	≤0.010

3) adhesive is high mould potassium-sodium water glass, and modulus 3.0-3.1, potassium sodium are than 2: 1-2.5: 1,42 ° of Be '-43.5 ° Be ' of concentration;

The weight ratio of electrode coating auxiliary material and adhesive is 1: 0.24.

Welding agent Formula Design characteristics of the present invention:

1. the acid-base value that at first relates to slag should have enough basicity to guarantee the degree of purity of deposited metal, makes every effort to non-metallic inclusion lacking very; 2. the character of thermophysical property, the especially vertical position welding of consideration slag, horizontal position welding, overhead welding is easily taken off slag and weld ripples forming, prevents the big droplet transfer, and the molten bath is full, is convenient to the welding operation; 3. the coating fusing point is moderate, should form certain sleeve, guarantees that welding rod has certain power of blowing, and discard electrode (being electrode tip) melts, and upper and lower fusing is inhomogeneous when preventing vertical position welding; 4. satisfying the mechanical property requirements of welding rod deposited metal, mainly is low-temperature impact toughness, and-60 ℃ of each monodromes are greater than 70J, but mean value will reach more than the 100J; 5. in deposited metal, raising along with transition Ni constituent content, low-temperature flexibility increases, under the low-down situation of the content of S, P, and S≤0.005%, P≤0.012%, meet this rule, when S, P were slightly high, along with the increase of nickel content, toughness descended on the contrary, reason is that the increase along with nickel content causes due to S, the P segregation, so look the component that the content of core wire S, P is determined nickel easily; 6) Ti and the B that uses trace realizes microalloying, and metallographic structure helps improving low-temperature flexibility and crystal grain thinning to reach acicular ferrite; 7) add the further crystal grain thinning of trace rare-earth element, obtain satisfied low-temperature flexibility.

Advantage of the present invention is: this welding rod is super low hydorgew sodium type high strength and high toughness welding rod, and welding technological properties is good, striking is easy, electric arc is soft, it is few to splash, take off slag easily, that weld ripples is shaped is careful, attractive in appearance, but all-position welding; Deposited metal purifies, refinement is good, has good low-temperature impact toughness and cracking resistance, the fabulous impact flexibility A of tool still under-60 ℃ of conditions _KVMonodrome 〉=70J, A _KVMean value 〉=100J; The diffusible hydrogen content of deposited metal is low, result of the test (mercury process)≤2.5ml/100g; Performance with good heat resistanceheat resistant crackle, cold crack and anti-reheat crack(ing); The adaptable specification of heat treatment of postwelding deposited metal is wide, and good practice of construction adaptability is arranged, and is widely used in 2000m ³Spherical ethylene tank, 2000m ³Ultra-large type low temperature spherical tanks such as propylene spherical tank, the welding of LPG spherical tank.

The specific embodiment

Embodiment 1:

A kind of welding rod that is used for the large scale low temperature spherical tank steel welding is made up of core wire, electrode coating and adhesive, and the welding rod production technology is made routinely, is about to the H08GX wire rod, cuts into core wire; The electrode coating auxiliary material is prepared mixing in proportion; Water glass binder is added in the auxiliary material mixed powder by 24% part by weight; With conventional welding rod production equipment and technology, core wire and mixed powder are made welding rod and oven dry.The composition situation is as follows among this embodiment:

1) core wire is H08GX welding rod wire rod, its contained chemical composition and percentage by weight such as following table: (%)

C	S	Mn	Si	P	Fe
						0.054	0.003	0.45	0.027	0.006	Surplus

2) electrode coating comprises following auxiliary material and percentage by weight such as following table: (%)

Marble	Fluorite	Rutile	Silicon powder	Ferromanganese	Ferrosilicon	Ferrotianium	Nickel powder	Ferro-boron	Molybdenum-iron	Iron powder
											33	17	7	5	5	3	8	10	1	0.5	10.5

, wherein the percentage by weight of S, P is in following auxiliary material: (%)

Coating auxiliary material title	Marble	Fluorite	Ferrosilicon	Ferrotianium	Iron powder	Silicon powder
							S	0.003	0.004	0.008	0.009	0.004	0.003
P	0.004	0.004	0.010	0.010	0.003	0.009

3) adhesive is high mould potassium-sodium water glass, and modulus 3.0-3.1, potassium sodium are than 2: 1-2.5: 1,42 ° of Be '-43.5 ° Be ' of concentration; The weight ratio of electrode coating auxiliary material and adhesive is 1: 0.24.

To detect by the welding rod that mentioned component is made, welding rod cured 2 hours through 380-400 ℃ earlier before soldering test, then according to the standard code of GB GB/T 5118-1995 low-alloy structural steel electrode, carry out deposited metal composition analysis, deposited metal Mechanics Performance Testing, deposited metal diffusible hydrogen content mensuration, welding conditions: the source of welding current is that dc reverse connection, weld heat input are that temperature is that 105-110 ℃, post weld heat treatment are 620 ℃ of insulation 1h between 12-17KJ/cm, road, with the stove cooling, testing result is as follows:

1) deposited metal composition percentage by weight (%) measured value:

Chemical element	C	S	Mn	Si	P	Ni	Mo	Ti	B
										Measured value	0.057	0.003	1.10	0.13	0.010	2.56	0.20	0.021	0.0038

2) deposited metal mechanical property measured value

3) adopt mercury process to measure the deposited metal diffusible hydrogen content, its diffusible hydrogen content is: 2.10ml/100g, 2.06ml/100g, 1.94ml/100g, 2.30ml/100g, mean value 2.10ml/100g.

Embodiment 2:

The manufacturing process of welding rod and detection method and embodiment 1 are identical, and the composition situation is as follows among this embodiment:

1) core wire is H08GX welding rod wire rod, its contained chemical composition and percentage by weight such as following table: (%)

C	S	Mn	Si	P	Fe
						0.056	0.004	0.44	0.025	0.005	Surplus

2) electrode coating comprises following auxiliary material and percentage by weight such as following table: (%)

Marble	Fluorite	Rutile	Silicon powder	Ferromanganese	Ferrosilicon	Ferrotianium	Nickel powder	Ferro-boron	Molybdenum-iron	Iron powder
											33	17	7	5	5	3	8	10	1	0.5	10.5

, wherein the percentage by weight of S, P control index is in following auxiliary material: (%)

Coating auxiliary material title	Marble	Fluorite	Ferrosilicon	Ferrotianium	Iron powder	Silicon powder
							S	0.002	0.004	0.008	0.008	0.004	0.003
P	0.003	0.005	0.010	0.009	0.003	0.009

3) adhesive is high mould potassium-sodium water glass, and modulus 3.0-3.1, potassium sodium are than 2: 1-2.5: 1,42 ° of Be '-43.5 ° Be ' of concentration; The weight ratio of electrode coating auxiliary material and adhesive is 1: 0.24.

To detect by the welding rod that mentioned component is made, testing result is as follows:

1) deposited metal composition percentage by weight (%) measured value:

Chemical element	C	S	Mn	Si	P	Ni	Mo	Ti	B
										Measured value	0.058	0.003	1.12	0.14	0.011	2.56	0.20	0.021	0.0040

2) deposited metal mechanical property measured value

3) adopt mercury process to measure the deposited metal diffusible hydrogen content, its diffusible hydrogen content is: 2.09ml/100g, 2.04ml/100g, 1.97ml/100g, 2.28ml/100g, mean value 2.10ml/100g.

The LB-65L welding rod with the Japanese kobe steel group of intensity rank that the welding rod of the foregoing description preparation and present China use is compared, and performance advantage is obvious, and the contrast situation is as follows:

	Akv (ballistic work-60 ℃) J	Deposited metal percentage elongation A%	The deposited metal mercury process is surveyed hydrogen content (ml/100g)
				LB-65L	80-90	20	3.5-4.0
This invention welding rod	104-159	27	1.94-2.3

Claims (1)

1. a welding rod that is used for minimum-60 ℃ of large scale low temperature spherical tank steels welding is made up of core wire, electrode coating and adhesive, and welding rod production technology manufacturing routinely, it is characterized in that:

1) core wire is H08GX welding rod wire rod, its contained chemical composition and percentage by weight such as following table: (%)

C S Mn Si P Fe 0.05-0.08 ≤0.004 0.30-0.60 ≤0.030 ≤0.006 Surplus

2) electrode coating comprises following auxiliary material and percentage by weight such as following table: (%)

Marble Fluorite Rutile Silicon powder Ferromanganese Ferrosilicon Ferrotianium Nickel powder Ferro-boron Molybdenum-iron Iron powder 30-40 13-17 4-7 3-5 3-5 3-4 6-8 8-10 0.5-1 0.5-1 Surplus

, wherein the percentage by weight of S, P control index is in following auxiliary material: (%)

Coating auxiliary material title Marble Fluorite Ferrosilicon Ferrotianium Iron powder Silicon powder S ≤0.005 ≤0.005 ≤0.010 ≤0.010 ≤0.005 ≤0.005 P ≤0.005 ≤0.005 ≤0.010 ≤0.010 ≤0.003 ≤0.010

3) adhesive is high mould potassium-sodium water glass, and modulus 3.0-3.1, potassium sodium are than 2: 1-2.5: 1,42 ° of Be '-43.5 ° Be ' of concentration;

The weight ratio of electrode coating auxiliary material and adhesive is 1: 0.24.