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第一汽车制造厂在技术革命中提出了翻番的口号,在翻番过程中,可锻铸铁快速退火是一个关键问题。为此第一汽车制造厂与哈尔滨工业大学铸工教研室成立可锻铸快速退火研究小组,在一九五八年硼鉍可锻铸铁快速退火达24小时成功的基础上继续进行研究,经过半年来的实验和生产考验成功地将退火周期压缩到16～18小时。但由于生产中有一个时期含硫量颇高,使得这一新工艺推广发生了一些困难,为了解决这一困难,化不利因素为有利因素,我们进行了以硫代替部分鉍的研究。在研究过程中系统地对硫在冷疑时阻碍石墨化的作用,在退火过程中的作用和硫对铁素体可锻铸铁金相组织和机械性能的影响进行了分析和总结,并同鉍的作用进行了比较。发现硫量提高一倍可以减少鉍量6～7倍。作高硫铁素体可锻铸铁最恰当的成分是:C=2.68～2.75%,Si=1.45～1,55%,Mn=0.35～0.45%,S=0.17～0.23%,p<0.1%,Bi=0.062～0.003%,B=0.002～0.003%。在昇降式密闭电阻退火炉中退火周期为30～32小时。可锻铸铁的机械性能σ_B=34～37公斤/毫米~3,δ=9～12%,H_B=131～149,这一硫代鉍的方案已为车间所采用并经过了大量生产考验。
The first automobile factory in the technological revolution put forward double the slogan, in the double process, rapid annealing malleable iron is a key issue. To this end the first automobile factory and the Casting Department of Harbin Institute of Technology set up a forging rapid annealing research group, in 1958, bismuth malleable iron rapid annealing for 24 hours on the basis of the success of continued research, after six months of experiments and The production test successfully compressed the annealing cycle to 16-18 hours. However, due to the high sulfur content in production during a certain period of time, some difficulties occurred in the popularization of this new technology. In order to solve this problem, the unfavorable factors are favorable factors, and we have carried out the research of replacing part of bismuth with sulfur. In the course of the study, the effect of sulfur on graphitization during the cold phase was systematically investigated. The effect of sulfur in the annealing process and the effect of sulfur on the microstructure and mechanical properties of ferrite malleable cast iron were analyzed and summarized. Compared. It is found that double the amount of sulfur can reduce the amount of bismuth 6 to 7 times. The most suitable composition of high-sulfur ferritic malleable iron is C = 2.68-2.75%, Si = 1.45-1.55%, Mn = 0.35-0.45%, S = 0.17-0.23%, p <0.1%, Bi = 0.062 ~ 0.003%, B = 0.002 ~ 0.003%. In the lift-type closed-end annealing annealing furnace annealing period of 30 to 32 hours. The mechanical properties of malleable cast iron σ_B = 34 ~ 37 kg / mm ~ 3, δ = 9 ~ 12%, H_B = 131 ~ 149, the bismuth thiobium solution has been adopted by the workshop and after a large number of production tests.