CN1158778A - Activator - Google Patents

Abstract

The present invention belongs to field of welding material, and the activator is mainly suitable for being used as an additive to metal welding wire. Its chemical components include in wt%:Li2CO3 8-40%, K2CO3 10-30%, Na2CO3 9-35%, TiO2 6-24%, MgO 3-12%, MnO2 6-24%, and CaF2 4-30%. It can reduce welding splash obviously, and when it is added into CO2-protected welding wire in the amount of 6-7 wt%, the welding splash rate is reduced from 10-12% to 2-3% and the properties of welding seam, including forming property, impact toughness and plasticikty, are improved.

Description

A kind of activator

The invention belongs to field of welding material.Mainly be applicable to add in the metal welding wire, splash, improve Weld Performance to reduce weld metal.

Wideling popularize the automatic or semi-automatic CO with the replacement manual welding of application ₂Gas is protected in the weldering, main problem be exactly when gage of wire thicker, when reaching Φ 2.0-Φ 3.0mm, metal splashes greatly, appearance of weld is bad, particularly the impact flexibility of weld seam and plasticity seriously reduce, and have so just influenced CO ₂Gas is protected applying of weldering.Many for this reason Welder authors have carried out fruitful research for many years from every side.Have from source of welding current characteristic, make current waveform and welding wire send the pulsed wire feeding that jointly controls to, aspects such as electric arc control are improved, and to reduce spatter, these methods are to the little standard CO of fine rule Φ 0.8-Φ 1.2mm ₂It is more remarkable to be welded into effect, has obtained promising result, but to the big standard CO of smart crin ₂Weldering produces little effect; From the welding material aspect, the domestic Li Peizu of Shandong Polytechnic Univ etc. adopt easily ionizable surface-active material K ₂CO ₃, CsCO ₃Spread upon welding wire surface Deng mixing, make the activation welding wire, reduce spatter, obtain certain effect, studies show that: spatter loss coefficient can drop to about 6% from about 10% and (see " solder technology " No5,1987, Li Peizu etc., the activation welding wire reduces the research that carbon dioxide arc welding splashes).In this prescription, because of containing the easy moisture absorption of cesium carbonate, and cost is higher, and the activator that spreads upon welding wire surface easily comes off, and inhomogeneous, the method is not easy for industrial production.

At the beginning of the eighties, many research work have been done aspect the spatter utilizing activator to reduce by the former Soviet Union.The activator of their development is by Na ₂CO ₃17～34%, CaCO ₃16～35%, MnO ₂8～40%, Al ₂O ₃6～32% 4 kinds of easily ionizable materials and surface reactive material are formed (N.M.VOROPALand L.M.BEL ' FOR, MECHANISED-CO2 WELDING WITH 3-4mm DIAMER ACTI VATEDWIRE, " WeldingReseaarrch Abroad) " APR, 1983).Total addition accounts for 3～6% of welding wire weight, and result of study shows that spatter loss coefficient can drop to 4%～5% from 10%～12%.In this prescription, owing to contain Al ₂O ₃, the easy moisture absorption, and do not have the dehydrogenation material, making the very difficult reduction of diffusible hydrogen content in the weld seam, impact flexibility is lower.

The object of the present invention is to provide a kind of activator, it is joined in the welding wire, can effectively reduce weld metal and splash, can improve appearance of weld again, improve weld seam impact toughness and plasticity.

In order to obtain optimum formula, the present invention is in Analysis for CO ₂Gas protects the mechanism that weldering is splashed and produced, and studied after the thermal conductivity of the ionization character of metal vapors in the arc atmosphere and metal vapors from Li ₂CO ₃, K ₂CO ₃, Na ₂CO ₃, TiO ₂, MgO, MnO ₂, CaF ₂In 7 kinds of compounds, adopt orthogonal design method, and utilize the characteristics that view is examined the droplet transfer characteristic and splashed and produce of taking the photograph at a high speed, in conjunction with mechanical performance analysis and the microscopic examination that the butt welded seam metal is done, draw activator optimum chemical composition proportioning: (weight %): Li ₂CO ₃8～40%, K ₂CO ₃10～30%, Na ₂CO ₃9～35%, TiO ₂6～42%, MgO3～12%, MnO ₂6～24%, CaF ₂4～30%.In this prescription, because of Li ₂CO ₃, K ₂CO ₃, Na ₂CO ₃In lithium, potassium, sodium all be active element, its Li ₂CO ₃, K ₂CO ₃, Na ₂CO ₃The total effective ionization potential of the suitable mixing of three kinds of easily ionizable materials is all lower than any one matter; And the TiO in the prescription ₂Can improve the microscopic structure in the weld seam, make the sheet columnar ferrite become acicular ferrite, improve weld seam low-temperature impact toughness and plasticity; Because CaF ₂Can effectively reduce the hydrogen content in the weld seam, so added a certain amount of calcirm-fluoride in this prescription; MgO and MnO ₂Adding be to take off slag automatically in order to improve the character of slag, to make.

The process for preparation of activator of the present invention is as follows: at first with Li ₂CO ₃, K ₂CO ₃Sieve respectively through 60～80 eye mesh screens Deng 7 kinds of compounds, 7 kinds of compound mixtures are even in institute then to ratio, add an amount of sodium silicate again and it is bonded together make granularly, put into oven for drying again, after 40 eye mesh screens sieve can use.

Compared with prior art, it is remarkable that activator of the present invention reduces spatter, when at CO ₂When the gas shield welding wire added 6～7% (weight ratio) activator, the spatter rate reduced to 2～3% by 10～12%, and can improve appearance of weld, increased the impact flexibility and the plasticity of weld metal.For Φ 2.0mm solid core welding wire, behind the adding activator, its weld metal-40 ℃ ballistic work can reach 56J.

Embodiment

The formula range of activator according to the present invention makes 3 kinds of concrete activators, and composition sees Table 1.Join that addition 6.6% (weight %) is by normal standard welding in the solid core welding wire of Φ 2.4, the activation welding wire A π-AH2 metal spatter loss coefficient of the mechanical performance of gained welding wire metal spatter loss coefficient and weld seam and former Soviet Union Φ 3.2 and the mechanical performance of weld seam contrast and see Table 2.

The concrete chemical composition of table 1 embodiment activator

The compound sequence number	??Li 2CO 3	??K 2CO 3	???Na 2CO 3	?TiO 2	????MgO	???MnO 2	???CaF 2
								????1#	????9.4	???17.6	????18.5	??24.0	????8.4	???14.5	????7.6
????2#	????10.4	???16.5	????17.5	??26.0	????9.8	???10.6	????9.2
								????3#	????9.8	???18.6	????18.4	??24.5	????9.7	???11.3	????7.7

The mechanical performance of table 2 embodiment spatter rate ψ and weld metal

Examples of properties	Spatter loss coefficient ψ %	???σs ??MPa	????σb ????MPa	????δ5 ????％	20 ℃ of ballistic works (J)	Ballistic work (J)-40 ℃
							????1#	????2.62	??476	????565	???30.5	????172	????56
????2#	????2.45	??485	????575	???30	????168	????54
							????3#	????2.86	??460	????560	???31	????176	????54
??Aπ-AH2	????3.90	??490	????576	???29.5	????89	????32

Claims (1)

1, a kind of activator is characterized in that its chemical composition (weight %) is: Li ₂CO ₃8～40%, K ₂CO ₃10～30%, Na ₂CO ₃9～35%, TiO ₂6～42%, MgO3～12%, MnO ₂6～24%, CaF ₂4～30%.