The present invention relates to a hot-dip galvanized automotive exterior plate bake hardening steel. Its chemical composition is as follows: C: 0.0018-0.0030%, Si: 0.18-0.27%, P: 0.030-0.050%, Mn: 0.45-0.60%, Als: 0.02-0.045%, Nb: 0.006-0.010%, Ti: 0.001-0.005%, limiting elements: S: 0.008%, N: 0.003%. First, the molten iron is desulfurized, converter smelted and RH vacuum treated; then the molten steel is continuously cast into billets, and the billets are continuously rolled into strips by hot strip rolling and pickled by a combined acid rolling mill; then the hot rolled strips are cold rolled for five passes and hot galvanized, polished and stretched. After that, hot dip galvanized bake hardening steel is produced. The steel sheet produced by the invention has low yield strength before stamping forming, and is convenient for processing the parts. After forming, the yield strength of the parts is improved by strain aging steel sheet in the process of painting and baking, and the parts show high anti-depression performance. At the same time, the steel sheet has room temperature non-aging property.
【技术实现步骤摘要】
一种热镀锌汽车外板烘烤硬化钢及其制造方法
本专利技术涉及低碳钢
,具体涉及一种热镀锌汽车外板烘烤硬化钢及其制造方法。
技术介绍
烘烤硬化钢(英文BakeHardeningSteel简称BH钢)主要是以超低碳钢为基础,超低碳烘烤硬化钢对成分要求非常严格,不仅要求钢质纯净,而且要求成分精确控制,尤其是钢中的C含量既不能太低,也不能太高,太低容易造成成品固溶C偏低,BH值偏低,达不到烘烤硬化强度30MPa要求;太高有可能造成成品BH值偏高,钢板抗自然时效性能变差。
技术实现思路
为克服所述不足,本专利技术的目的在于提供一种热镀锌汽车外板烘烤硬化钢及其制造方法,成形之后零件在涂漆烘烤过程中通过应变时效钢板的屈服强度提高,零件表现出较高的抗凹陷性能,同时钢板具有常温非时效性。本专利技术解决其技术问题所采用的技术方案是:一种热镀锌汽车外板烘烤硬化钢,其化学成分以质量百分比计算如下:C:0.0018~0.0030%、Si:0.18~0.27%、P:0.030~0.050%、Mn:0.45~0.60%、Als:0.02~0.045%、Nb:0.006~0.010%、Ti:0.001~0.005%,限制元素:S:0.008%以下、N:0.003%以下,余量为Fe。一种热镀锌汽车外板烘烤硬化钢的制造方法,包括以下步骤:D1、首先经铁水脱硫、转炉冶炼、RH真空处理;D2、然后将钢水进行连续铸造成钢坯,连铸坯经热连轧成钢带,用酸轧联合机组对热轧钢带进行酸洗;D3、随后进行5道次的冷轧制得带钢,冷轧压下率控制在80~90%范围内,经热镀锌、光整、拉矫后,生产出热镀锌烘烤硬化钢。其 ...
【技术保护点】
1.一种热镀锌汽车外板烘烤硬化钢,其特征在于:其化学成分以质量百分比计算如下:C:0.0018~0.0030%、Si:0.18~0.27%、P:0.030~0.050%、Mn:0.45~0.60%、Als:0.02~0.045%、Nb:0.006~0.010%、Ti:0.001~0.005%,限制元素:S:0.008%以下、N:0.003%以下,余量为Fe。
【技术特征摘要】
1.一种热镀锌汽车外板烘烤硬化钢,其特征在于:其化学成分以质量百分比计算如下:C:0.0018~0.0030%、Si:0.18~0.27%、P:0.030~0.050%、Mn:0.45~0.60%、Als:0.02~0.045%、Nb:0.006~0.010%、Ti:0.001~0.005%,限制元素:S:0.008%以下、N:0.003%以下,余量为Fe。2.一种热镀锌汽车外板烘烤硬化钢的制造方法,其特征在于:包括以下步骤:D1、首先经铁水脱硫、转炉冶炼、RH真空处理;D2、然后将钢水进行连续铸造成钢坯,连铸坯经热连轧成钢带,用酸轧联合机组对热轧钢带进行酸洗;D3、随后进行5道次的冷轧制得带钢,冷轧压下率控制在80~90%范围内,...
【专利技术属性】
技术研发人员:胡华东,佟松泽,刘铮,
申请(专利权)人:山东钢铁集团日照有限公司,
类型:发明
国别省市:山东,37
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