CN105734631A - Electroplating solution and electroplating method for roughening treatment of cold-rolled roller - Google Patents

Abstract

The invention discloses an electroplating solution and electroplating method for roughening treatment of a cold-rolled roller. The electroplating solution comprises chromic acid, sulfuric acid and hydrogen peroxide. The electroplating method comprises the steps that firstly, pretreatment is conducted on the surface of the roller before plating; secondly the roller is completely immersed in the electroplating solution, and the distance between the roller surface and the insoluble anode, the temperature of the electroplating solution and the rotation speed of the roller are set; thirdly an electroplating cycle of the roller comprises a pulse current stage and a direct current stage, the time of the pulse current stage is 960-3000 ms, the breakover current density is 10-30 A/dm<2>, the time of the direct current stage is 480-2400 ms, and the current density is 1-10 A/dm<2>; and finally, after the thickness of a plating layer of the roller reaches 15-120 micrometers, electroplating is finished. By the adoption of the electroplating solution and electroplating method, a chromium coating of the specific spherical micro structure is formed on the surface of the roller, and the purpose of meeting the surface texture requirements such as specific roughness and peak value density is achieved.

Description

The electroplate liquid of roll for cold rolling frosting treatment and electro-plating method

Technical field

The present invention relates to the electroplate liquid of a kind of roll for cold rolling frosting treatment and electro-plating method.

Background technology

Surface texturing cold-reduced sheet, namely surface has the cold-reduced sheet of certain roughness requirement, is the important materials of auto industry and household electrical appliances industry.Texturing cold-reduced sheet may insure that and keeps closed state in steel plate deformed process in lubricating oil hole under high pressure, cushion pad is formed between steel plate and grinding tool, improve antifraying property, make it have good covering with paint and punching performance, and textured steel sheet is exactly formed through the roll for cold rolling rolling of frosting treatment by surface.In order to produce the cold rolling textured steel sheet of high-quality, first having to roll for cold rolling is carried out frosting treatment, then milling train uses Texturing Surface of Roll to roll out required cold rolling textured steel sheet.

Processability and coating performance are to weigh the important indicator that cold-rolled steel sheet uses, and this all has close relationship with the characteristic parameter of belt steel surface pattern.The most basic parameter of belt steel surface pattern is roughness (Ra) and peak value (Pc), different roughness and peak density distribution means average crest-trough height different with crest number.Bigger roughness can form mutually isolated lubrication pit, is conducive to improving the friction shaping characteristic of strip steel；The pattern of equally distributed roughness, high peak density and random distribution, it is possible to reduce optical fringe, avoid orange peel effect, is conducive to improving the japanning optical characteristics of strip steel.Thus, Ra, Pc are the key factors controlling strip steel serviceability.

At present, conventional roller texturing processes technique mainly shot-peening texturing (SBT) technique and electric spark texturing (EDT) technique, and two kinds of roughing methods of SBT and EDT are all deformed or local melting by roll surface material plasticity, forms the texturing pattern of indent on surface.These processes all affect the serviceability of roll surface material to a certain extent, its roll surface pattern is made up of many spikes being prone to fracture and wear and tear, affecting maintenance performance and the anti-wear performance of roll surface material roughness, the decay of roll surface roughness is the main cause causing roll change.Therefore explore and develop more advanced roller surface texturing technology, having become the urgent needs that current cold-reduced sheet produces.

US Patent No. 6319385B1 describes a kind of method of roll surface electrodeposited chromium texturing, the patent describe the method adopting three layers coating to obtain texturing effect: ground floor is direct current electrode position nickel dam, the second layer is direct current electrode position hard chromium layers, and third layer adopts staircase waveform electric current to obtain the required texturing chrome plating of roll work；The method operation is many, add implement operation cost and difficulty, its current waveform adopted relatively is difficult to, to power-supply device require many compared with electroplating bath components that is high and that use, containing toxic and that corrosivity is very strong silicofluoric acid.US Patent No. 6478943B1 proposes a kind of electrodeposited chromium roughing method, and it is less that the method obtains coating roughness, it is difficult to meets and produces needs.

Summary of the invention

The technical problem to be solved is to provide electroplate liquid and the electro-plating method of a kind of roll for cold rolling frosting treatment, this electroplate liquid and electro-plating method overcome that the roughness decay that traditional cold rolling roller texturing processes is too fast, service life is low, surface topography pits more than protruding, be unfavorable for that strip steel is to defects such as the duplications of its surface roughness, form the chromium coating with specific spherical microstructure at roller surface, reach the purpose of the superficial makings requirement such as specific roughness, peak density.

For solving above-mentioned technical problem, the electroplate liquid of roll for cold rolling frosting treatment of the present invention includes chromic acid 180～300g/L, sulphuric acid 1.5～3g/L, hydrogen peroxide 8～20g/L.

The electro-plating method of a kind of roll for cold rolling frosting treatment comprises the steps:

Step one, roller surface is carried out Pre-treatment before plating；

Step 2, employing electroplate liquid described in claim 1, be totally submerged in electroplate liquid by roll, and roll surface and insoluble anode distance are 50～400mm, and temperature of electroplating solution is 45～58 DEG C, and roll rotational speed is 1～5 turn/min；

Step 3, one plate cycle of roll include pulse current section and DC current section, and the time of pulse current section is 960～3000ms, and conducting current density is 10～30A/dm²；The DC current section time is 480～2400ms, and electric current density is 1～10A/dm²；

Step 4, after roll coating reaches 15～120 μm, terminate plating.

Further, the current lead-through time of described pulse current section is 20～200ms, current-off time is 10～100ms.

Further, roller surface Pre-treatment before plating includes:

1), to roller surface carrying out machine glazed finish process, remove surface oxide layer and rejected region, being then polishing to rough surface is 0.5 μm；

2), use the greasy dirt on acetone cleaning roller surface and metal debris, then rinse with clear water；

3), using plating conventional alkaline degreasant solution wiping roller surface, solution temperature is 50 DEG C, then rinses with clear water；

4), roll being carried out electrolytic degreasing, roll is immersed in degreasing fluid, and degreasing fluid temperature is 50 DEG C, and electric current density is 5.0A/dm², the process time is 2min, then takes out roll, rinses with clear water；

5), using plating conventional acid etching solution that roll carries out activation processing, the etch time is 1min, then rinses with clear water.

Owing to electroplate liquid and the electro-plating method of roll for cold rolling frosting treatment of the present invention have employed technique scheme, namely this electroplate liquid includes chromic acid, sulphuric acid and hydrogen peroxide；First roller surface is carried out Pre-treatment before plating by this method；Then roll is totally submerged in electroplate liquid, sets roll surface and the distance of insoluble anode, temperature of electroplating solution and roll rotational speed；And one plate cycle of roll includes pulse current section and DC current section, and the time of pulse current section is 960～3000ms, and conducting current density is 10～30A/dm²；The DC current section time is 480～2400ms, and electric current density is 1～10A/dm²；After roll coating reaches 15～120 μm, terminate plating.This electroplate liquid and electro-plating method overcome that the roughness decay that traditional cold rolling roller texturing processes is too fast, service life is low, surface topography pits more than protruding, be unfavorable for that strip steel is to defects such as the duplications of its surface roughness, form the chromium coating with specific spherical microstructure at roller surface, reach the purpose of the superficial makings requirement such as specific roughness, peak density.

Accompanying drawing explanation

Below in conjunction with drawings and embodiments, the present invention is described in further detail:

Fig. 1 is the current waveform figure of a plate cycle in this electro-plating method；

Fig. 2 is the texturing coating surface morphology schematic diagram adopting this electroplate liquid and electro-plating method to obtain.

Detailed description of the invention

Embodiments of the invention are shown in table 1 below and table 2:

Table 1

Table 2

	Ta(ms)	Tb(ms)	Tab(ms)	Tcd(ms)	Ia(A/dm2)	Icd(A/dm2)
							Embodiment 1	20	10	480	2000	100	10
Embodiment 2	30	15	960	1440	150	30
							Embodiment 3	90	30	1440	960	200	50
Embodiment 4	150	50	2000	480	250	80
							Embodiment 5	200	100	2400	480	300	100

As it is shown in figure 1, in table 2, in a plate cycle T, T_abFor pulse current section time, T_cdFor DC current section time, T_aFor current lead-through time, T in the pulse current section time_bFor current-off time, I in the pulse current section time_aFor the conducting current density in the pulse current section time, I_cdFor the electric current density in the DC current section time；Wherein T=T_ab+T_cd, T_ab=K(T_a+T_b),K=1、2、3…

The coating roughness of the embodiment 1 to 5 listed by table 1 and table 2 and peak density are in Table 3:

Table 3

	Embodiment 1	Embodiment 2	Embodiment 3	Embodiment 4	Embodiment 5
						Roughness (μm)	1.2	2.58	4.49	3.83	4.24
Peak density (pks/cm)	47	112	98	89	73

As in figure 2 it is shown, this method forms the chromium coating with certain texturing effect at roller surface, pair roller plane materiel material does not affect, its anti-wear performance depends entirely on the hardness of chromium coating, owing to chromium hardness is significantly high, there is good wearability, it is possible to increase substantially the service life of Texturing Surface of Roll.In a plate cycle T, increase pulse current section time T_ab, roughness substantially increases；In a plate cycle T, increase DC current section time T_cd, roughness reduces；Increase the conducting current density I in the pulse current section time_a, coating roughness improves, but peak density reduces；Increase the electric current density I of DC current section time_cd, coating roughness first reduces and increases afterwards, but peak density reduces to some extent；This electro-plating method can pass through to set electroplating technological parameter, thus obtaining desired roller surface frosting treatment effect, in embodiment 1 to 5, all can obtain appearance uniform, adhesion good, the texturing chromium coating of hardness high (850-975Hv), meets the superficial makings requirements such as the roughness of roller surface frosting treatment, peak density.

Claims (4)

1. the electroplate liquid of a roll for cold rolling frosting treatment, it is characterised in that: this electroplate liquid includes chromic acid 180～300g/L, sulphuric acid 1.5～3g/L, hydrogen peroxide 8～20g/L.

2. the electro-plating method of a roll for cold rolling frosting treatment, it is characterised in that this method comprises the steps:

Step one, roller surface is carried out Pre-treatment before plating；

Step 2, employing electroplate liquid described in claim 1, be totally submerged in electroplate liquid by roll, and roll surface and insoluble anode distance are 50～400mm, and temperature of electroplating solution is 45～58 DEG C, and roll rotational speed is 1～5 turn/min；

Step 3, one plate cycle of roll include pulse current section and DC current section, and the time of pulse current section is 960～3000ms, and conducting current density is 10～30A/dm²；The DC current section time is 480～2400ms, and electric current density is 1～10A/dm²；

Step 4, after roll coating reaches 15～120 μm, terminate plating.

3. the electro-plating method of roll for cold rolling frosting treatment according to claim 2, it is characterised in that: the current lead-through time of described pulse current section is 20～200ms, current-off time is 10～100ms.

4. the electro-plating method of roll for cold rolling frosting treatment according to claim 2, it is characterised in that: roller surface Pre-treatment before plating includes:

1), to roller surface carrying out machine glazed finish process, remove surface oxide layer and rejected region, being then polishing to rough surface is 0.5 μm；

2), use the greasy dirt on acetone cleaning roller surface and metal debris, then rinse with clear water；

3), using plating conventional alkaline degreasant solution wiping roller surface, solution temperature is 50 DEG C, then rinses with clear water；

4), roll being carried out electrolytic degreasing, roll is immersed in degreasing fluid, and degreasing fluid temperature is 50 DEG C, and electric current density is 5.0A/dm², the process time is 2min, then takes out roll, rinses with clear water；

5), using plating conventional acid etching solution that roll carries out activation processing, the etch time is 1min, then rinses with clear water.