304 hot rolled stainless steel seamless pipeTransformation of precipitation - hardening stainless steels, their organization to stabilize the austenite organization, heat treatment is unable to change the Organization, to that end, can only through joining the precipitation strengthening element, through aging treatment and strengthening. Precipitation - hardening stainless steel among sensitive to chemical composition, mechanical properties, is sensitive to heat, so the production specification for this type of heat treatment process of steel must be in strict accordance with the action.