79
TTHA in the e lectrodeposition process w as d iscussed as we l. l It w as found that HHTA w as ab le to effectively eli m ina te the neg a tive effect caused by the iron i m purity and re m arkably i m prove the coa ting qua lity . T he reason lay in tha t TTHA w as capab le o f e li m inating the interference caused by iron ( Ⅱ ) by w ay o f che la ting effect and taking part in the e lectroplating pro cess . K ey w ords : high speed tin plating ; TTHA; iron i m purity ; remov a; l m echan ism Analysis of Cau ses L ead ing to Failure of H igh Pressure H y d rogen Adjacent P ipe lines U sed for H yd rogenated Refin ing of D iese l O il ZHAO M ing juan ( A nshan O il R efinery Fac to ry , L iaoy ang Branch o f P etroCh ina Co . L td. , A nshan 114011, Ch ina) Cailiao Baohu 2006 , 39 ( 6), 66 ~ 68( Ch) . T he causes lead ing to the exp losion fa ilure of the high pressure hydrogen adjacent p ipe lines used for the hydrogena ted refin ing of d iesel o il in an o il re finery facto ry w ere analyzed in deta i. l Itw as found tha t the b lowout and fa ilure of the p ipe lines w as attributed to the properties w orsening o f the m ate rials subject to harsh w orking conditions in clud ing high te m pera ture and h igh pressure in the presence o f fla mm able hydrogen gas and corrosiveH 2 S gas , w hich cou ld read ily cause hydrogen induced corrosion o f the pipe line . T hus it was m perative to str ictly abide by N elson curve in selecting proper i p ipe line m ater ia ls so as to ex tend the se rv ice life of the p ipelines . K ey w ords : high pressure p ipe line ; fa ilure ana ly sis; hydrogenated refin ing o f diese l o il Application of N eu tral E lectrolysis Descaling T echnology in P ick ling of Stain less Stee l YUAN Jin zhao ( Co ld Ro lling M ill o f Sta in less Stee, l T a iyuan I ron and S tee l G roup Co . , L td, T a iyuan 030003, China) Cailiao Baohu 2006 , 39( 6), 69 ~ 70 ( Ch). In the light o f the i m po r tance o f sod ium sulfa te neutra l e lectro lysis descaling in c lean e lectro lys is processes , a deta iled analysisw as made w ith respect to the concentration, temperatu re , and p H va lue of the e lectro lyte , and electro lysis current , stee l sheet th ickness , e lectrode gap , and recyc ling o f the electro ly te so lution. T he effects o f various e lectro lys is para m ete rs on the surface quality of the pick led stee l shee t were investigated . A s the results , for the produc tion line o f continuous annea ling and p ickling o f the co ld ro lled sta inless stee , l it w as feasib le to ach ieve satisfied surface qua lity o f the stee l sheet by pick ling in 20 % N a2 SO4 so lution a t a te m pe rature o f 85 , Cr6+ conten t 3~ 5 g /L , pH va lue 5~ 7 , cathode cur rent dens ity 10 ~ 14 A /dm 2 , electro ly te c irculation flux 200 m 3 /h, g ap be t w een uppe r and low er electrodes 200 ~ 300 mm ( wh ich w as contro lled by accounting for the shape of the stee l strip) , for a cathod ic process up to 10~ 12 s. K ey w ords: N a2 SO4; neutra l electro lys is desca ling ; sta inless stee ; l p ickling ; app lication Simu ltaneous D eterm in ation of Cobalt and N icke l in T in N icke l A lloy E lec trop lating Solu tion by Two W avelen gth Sp ec trophotom etry W U W e i m ing , YANG P ing ( D epartm ent of A pplied Che m istry , Jiangx i U niversity of Sc ience and T echno logy , G anzhou 341000, China) Cailiao B aohu 2006, 39 ( 6), 71 ~ 73 ( Ch). T he Co2+ and N 2+ i in Sn N i env ironm enta lly acceptable e lectrop lating solu tion w ere si m ultaneously determ ined by means o f two w ave length
2+ 2+ 2+
3 小
结
经过反复试验和生产实践, 逐渐掌握了工艺要 点, 获得了满意的锰盐磷化膜层: ( 1)锰盐磷化膜层 分布均匀, 结晶细致 , 具有 灰色至灰黑色的无光面层 , 无未处理区域, 未出现 不规则、 片状或粉状膜层 ; ( 2)磷化膜厚度均匀 , 平均膜层厚层均在 7 m 以上 ; ( 3)经过封闭处理后的锰盐磷化膜 , 经受至少 72 h 盐雾试验未出现腐蚀现象 ; ( 4)除氢处理后的随槽试片经 过慢弯曲试验 法检测, (
[ 2]
1 . 4 磷化液的分析 ( 1 ) 总 酸度 : 使 用酚 酞指 示剂, 移取 槽 液 10 mL, 用 0. 1 m o l/L N aOH 滴定。 ( 2)游离酸度 : 使用甲基橙指示剂 , 移取槽液 10 m L, 用 0 . 1 m o l/L NaOH 滴定。 ( 3) F e : 移取槽液 10 mL, 加 1 1 . 5 磷化膜的性能测试与评价 ( 1)外观 : 合格的磷化膜层应是连续、 均匀和 细致的结晶, 颜色为灰色或灰黑色。 ( 2) 厚度 : 采用磁性测厚仪 , 每件随槽试样取 10 个测量值。 ( 3) 耐蚀性: 进行 5 % NaC l盐雾喷雾试验 72 h 后表面不超过 3 个腐蚀点为合格。 ( 4) 无脆性试验 : 采用慢弯曲试验 可以判断 工艺流程 工件表面准备→溶剂清洗→吹砂→装挂→碱 清洗→冷水洗→热水洗→锰盐磷化→冷水洗→封 闭→干燥→除氢→涂油。 1. 2 锰盐磷化液配方和工艺参数 PL 复合磷化液 Fe
2+
,
145 g /L 1. 5~ 3. 0 g /L 50~ 75 点 ( 10 3) 点 90~ 98 12~ 15 m in