LP-Z301Blackening agent at room temperature

2018/07/06

(Specially recommended) LP-Z301 Normal Temperature Blackening Agent
The recently developed "LP-Z301 steel blackening agent at room temperature" developed by our company has the advantages of stable solution, short blackening time, suitable color, convenient and simple process, sufficient raw materials and low cost, especially the adhesion of the blackened film layer. Corrosion resistance is significantly better than the original product. It has the characteristics of no pollution, energy saving, and no steel type selectivity. In order to solve the long-term alkaline high-temperature blackening pollution, high energy consumption, and the choice of rigidity, a new approach has been opened up, which provides ideal advanced technology for the blackening treatment of steel products of various manufacturers.

 Process technology introduction

I. Main features:
1. Save energy. Blackening does not require electricity at all. Compared with alkaline high-temperature blackening, it saves 100% of electricity.
2, improve work efficiency. Basic blackening takes 40-80 minutes, and this blackening agent only takes 1-5 minutes.
3. The cost of blackening is low. The equipment is simple, only plastic, ceramic tanks and basins are needed, and it is easy to operate.
4. Strong process adaptability. There is no choice for rigidity, and the iron and steel parts with different carbon content and different surface addition states can obtain the consistent effect of the overall surface color, and the blackened workpiece can be sealed by dehydration oil and heat invasion.
5. Strong adhesion. Strong anti-corrosion, the surface color of the workpiece after darkening will increase with the storage time.

II.main technical indicators:
The blackening agent is blue liquid, no mechanical impurities, odorless, non-combustible, non-explosive, non-corrosive, and safe to transport.
PH value: 2-2.5 Density: 1.04 Water insoluble matter: <1%.

III. performance indicators:
Refer to the standard WJ535-82 "Technical Conditions for Alkali Chemical Oxidation of Iron and Steel Parts" issued by the Ministry of Ordnance Industry after blackening:
1. Use 3% copper sulfate to drip test, and the discoloration time (15-20 ℃) should not be less than 32 seconds.
2, meet the standard after soaking in 3% neutral sodium oxide aqueous solution for 2 hours.
The results show that the performance of the workpiece treated by the blackening agent meets the requirements of the ministerial standard.

IV. Usage:
1, Processing steps:
Outfitting frame → oil removal → water washing → rinsing → rust removal → rinsing → rinsing
Immersion dehydration antirust oil ← Replace frame ← Rinse ← Water rinse ← 2 Normal temperature black ← 1
Hot engine oil ← Replace the frame ← Boiling water dehydration ← Rinse ← Water rinse ← -3
Dipping sealing lacquer ← boiling water dehydration ← rinse ← water rinse ← -------- 4
Note: (1) above is the pre-processing: (2) (3) (4) is the post-processing of the three methods.
2, pre-processing steps:
(1) Degreasing: All parts that need to be blackened must be degreased on the surface (degreasing method: metal normal temperature cleaning agent can be used to degrease, and alkaline high temperature degreasing can also be used), otherwise they will not become black or Piebald. After degreasing, wash the parts with hot water and rinse them with running water.
(2) Washing with water: Rinse with tap water for 0.5-1 minute, then rinse with running tap water.
(3) Derusting: Lightly rusted machined parts can be pickled with hydrochloric acid (1: 1 ratio of industrial hydrochloric acid and water) for 1-5 minutes: parts with thick oxide scale can be heated at 180-250 g / l sulfuric acid Remove rust.
(4) Water washing: first rinse with tap water and then rinse with running tap water for 0.5-1 minute.
3. Blackening process:
Immediately immerse the parts without grease and rust spots in the blackened working fluid after cleaning, lift the gap up and down 2-3 times, and take it out after immersing for 3-5 minutes (the initial concentration of the solution is preferably about 3 minutes), using tap water Rinse and rinse.
4. Post-processing steps: Choose one of three different processing methods:
1 (1) Dehydration oil sealing: immerse the parts that have been blackened, rinsed and rinsed with water in dehydration antirust oil for 3-5 minutes, and lift it up and down 3-5 times.
(2) Hot dipping oil: immersed in boiling aqueous solution for 1-3 minutes, and then hot dipping motor oil or various antirust oils can improve the corrosion resistance (the effect of dipping dehydrated antirust oil is better)
(3) Impregnating sealant: high-end parts (such as photographic equipment, optical instruments) need high wear resistance and good gloss. After dehydrating with boiling water, impregnating the sealant. (Such as acrylic paint, polyurethane paint, etc.)
5. Solution maintenance:
When the efficiency of the blackening agent decreases, the blue-green color of the solution gradually fades, the pH value rises to about 3.0, and white precipitation occurs, indicating that the blackening agent is aging. At this time, you can filter and clarify, separate the precipitate, and then add a blackening agent stock solution (measured with a precision test paper with pH 0.5-5) until the pH returns to the range of 2-2.8 and you can continue to use. It is best to use two tanks, one tank to work and one tank to clear the sediment.
6. Common defects in blackening, their causes and troubleshooting methods:

Serial number	Defect feature	Cause	Method of exclusion
one	Blackened film layer is uneven	1、   Degreasing of the workpiece is not clean	1、   Step up degreasing and rinse with water.
		2、   Incomplete cleaning	2、   After degreasing, wash with hot water and rinse with cold water
		3、   Artifacts overlap	3、   Shake the workpiece, considering from the fixture.
two	The surface of the part is loose and the bonding force is not strong	1、   Darkening is too long or too short.	1、Strict process and proper control of time
		2、   Residue on part surface	2、Strengthen the pre-treatment of darkening
three	Darkening film color	1、  Darkening time is too short	1、   Prolong blackening time
		2、   Insufficient ingredients	2、   Adjust or change solution
four	Poor gloss and rust spots	1、   Too much water in dehydrated oil	1、   Remove water, check dehydrated oil or replace
		2、   Short parts dehydration time	2、   Prolong dehydration time
five	Blueness is worse than alkaline blushing	1、   Blackening has not fully functioned	1、   Leave it for one day after darkening
		2、   The oxide layer of the part has not been removed	2、   Strengthen handling before darkening
six	Workpiece has spots		Non-oiled parts can be re-issued after flushing with water for 0.5-1 minutes
seven	Non-conforming product repair		10% dilute nitric acid can be used to remove the blackened film and re-blacken it

other instructions:
1. The adhesion of the blackened film layer increases with the storage time. The longer the time, the better the adhesion. After the blackened parts are sealed with dehydrated antirust oil, it is best to store them for one day before using them.
2. This product is a concentrated solution, diluted 1: 4 when used, and each kilogram of concentrated solution can blacken 30-100 kg of black steel (the surface is called about 3-4 square meters)
3. This blackening agent is not only suitable for soaking and blackening parts, but also suitable for painting, coating and blackening of large parts.
4. During the blackening process of this solvent, a small amount of precipitation occurs, which does not affect the quality of blackening. (Note: When working fluid is not in use, the sediment needs to be removed)
5.The solution should be stored in a dark place to prevent sunlight, high temperature and antifreeze. The storage period should not exceed one year.